In our realm, where there's a good guy, there's some other guy preparing to steal the latter's lunch money. This douchebag always has petty goons (some are (blond) girls) which will do anything to earn some bucks & kiss a bigger ass.
Remember that crazy time right after High School when your parents told you to carry on with your studies, go into college, meet a nice, accesible, in-your-league, smart but not completely independent girl, find a proper job, pay your taxes, marry, have kids and grow old like any other dude, but you said: "Hell, no, first i'm gonna take all my waiter tips and go to Europe to get laid old-continent style, yeahhhh!"? Well, how that worked out for you? Fucking Air France lost your baggages, french policemen inocently mistook you for a drug dealer because of your 16hrs-flight-next-to-a-couple-of-fat-sweaty-middle-age-men dreadlocks and your laid back attitude while all of your belongings AND your passport where in your backpack!
oh, mommy, why didn't i listen to you
So you spent the next 3 to 5 years in little french prison next to a couple of hobos who got caught giving each other a blowjob by the carrousel at the Eiffel Tower (which despite your time in France you haven't got the chance to see). By the time you get out, most of your brains cells are completly useless due to the fact that you were never really interested in reading so all you could do in your free time was get drunk (frenchmen give wine to the inmates right? i mean, they give it to babies, so there's no moral boundaries there) and eventhough you have now learned enough french to become a proud tramp, your american sense of misplaced patriotism would never ever allow you to depend on a dirty (i'm guessing) european bastard, you wander the streets alone, stupid and utterly helpless.
What may you do then? Who gives a shit for an american vagrant in european soil?Certainly not the americans since you don't have a passport!, and certainly not your momma since you didn't care for her wisdom when you had to! So, like every other former quarterback in your possition, you decide to help criminal masterminds make their wishes come true.
Who'd've known! It IS in the yellow pages
As the allmighty Wiki could tell you, the word "henchman" referes to those little guys who had to take care of the rich and pretty people's horses. So to say, stable staff. Not devil followers, nor criminals. However, thanks to the evolution of lenguage and the misconceptions of those ridiculous folks of yesteryear, it became sinonym of someone who wishes to climb the stupid ladder of criminal enterprises. Of course, being slowsighted, henchmen "know" they would only climb a step or two and that's it, you may become the favorite of the Boss, but never would you become the Boss himself, except in the unlikely case that you're Jack Nickolson, know a bit of chemistry and have a "thing" with the Boss' mistress. But that almost never happens.
So you may be one of these guys:
a) The poor fellow driven mad by a capitalist, forever-in-war, discriminating, unjust, unsafe, world.
b) The loser whose wife bosses around telling to bring some goddamned food to the table "or else..."
c) An ex-military whose goverment has let down one to many times, whose true love was banging his best friend while he got shot in the ass by some douchebag who had never even heard of the concept of shaving, and you're totally unqualified to be told what to do by a cocky brat wearing a tag that says: McDonalds Regional Manager coz' then your traning may kick in and that guy's head would end up in somebody's bic mac.
In any case, you won't be living all that long to worry about the world, the wife, the cocky managers, since, as a henchman, there's always someone getting ready to kill you.
In Real Life:
Odd are that your boss will tell you to do something you just won't be able to do at some point of your career, like wacking your best friend since he's a rat (he WAS fucking your girlfriend while you were fighting a stupidass war) to telling him the truth about whether he looks cool with his Elvis-like sideburns. He's probably goint to kill you himself. Or the military (you old pals!), the police (evil minions themselves), or the competition.
Say hello to a guy who really doesn't know that he's utterly fucked
In Fantasy World:
Well, like that guy from Stranger than Fiction, you have to find out in what genre you live since you may be killed by a superhero with the powers and the looks of a god!
"yeah, i'd fuck myself"
Or by some foxxy lady with absolutly no powers whatsoever, unless you count hair-that-defies-gravity a superpower.
Shazam! I just kicked you in the nuts, repetedly!
Or simply that your employer tells you to kill your colleagues in order to get a bigger cut yourself only to be killed by your boss no longer than 15 minutes after the beginning of the film.
Thing is, you will not be able to enjoy your hard hard hard earned cash, no matter who's your employer, the world will carry on spinning, and even if your girlfriend was a lying bitch, "bros before hos" is still a code by which you rule your life, so there's gotta be a better way to make easy bucks, fool everybody into believing you have a clue what you're doing, and still keep a little dignity when you get home.
If you've kept reading til' this point, you'd've realized that there really isn't any point in pursuing a career in the evil henchmen department, nonetheless, as some other (far smarter) reader might now, there are times in the life of a person when he just doesn't get to choose between the safe, boring, average life, or the oh-my-god-i'm-gonna-be-killed-by-a-guy-dressed-as-a-pimp sort of living.
yeah baby, hate the game and the player, specially the player
At some point, being a high school dropout, a crazy redneck, or a guy from Harlem rejected by rich people colleges eventhough he's an amazing writer (trained by freaking James Bond!), life just sort of shuts all around you, leaving you no choice but to grab your AK-47, and stand in line at the Henchmen Recrute Inc (main office is in L.A.) waiting for your turn. They are always hiring since most evildoers run out of goons as fast as Hugh Heffner runs out of viagra. For a couple weeks (if very, very lucky) your family will have a steady income, maybe you'll get to pay for your son's higher education or your wife's boob job (better choice) or buy a big house for your mother as a goodbye token of apreciattion for letting you fuck your life completely.
But hey, that's all asuming that being a evil minion actually pays, since most supervillians prefer to hire lunatics which will work for food and the oportunity to kill somebody (yeah, there are people who think that's something to look up to, like, texans?) There's always the chance that you survive working for a villain, just to get a bigger, scarier one make you do tryouts to see if you belong on his team, and he's not even going to pay you, except, of course, with the chance of being alive a little longer.
In retrospective, you should weight all of your options before putting all your eggs in the evildoer basket.