Or how about Richard Gere, who decides at the end of Pretty Woman that he should follow his heart and commit to a prostitute he knew for seven days? Hell, even Luke Skywalker turns off his targeting system and banks an entire planet's existence on space magic.
"Luke, you turned off your targeting system. Are you fucking stupid? Do you hate those people on that planet?"
A Better Alternative:
"Your heart gets a vote, but your brain gets veto power."
What they're telling you when they say "Follow your heart" is to set aside logic, ignore any potential consequences and trust that your emotionally fueled guess will be the right one. The problem with that is nobody really knows what they're talking about when they say "heart." Is it emotions? Gut instinct? A supernatural fate detector? In reality, the urges and cravings that spring up from your primal self are all based on such mundane, almost random factors. How much sleep you had the night before. Whether or not you have a headache. Depression. Your mood. Comet trails of old lessons floating around in your subconscious that you picked up from shows and songs when you were a kid.