No! Turn back! We'll say the brain and heart are first. And then courage.
Human beings belong to a group in the animal kingdom called deuterostomes, which also includes sea cucumbers, urchins, vertebrates, and everything else that literally comes to life anus first. In humans, after the sperm breaks through the egg's outer membrane like a blind, drunk bull, the embryo splits into many different cells, eventually becoming a blastula. The blastula cells rip open from the inside out, forming an opening called the blastopore, which as you may have guessed will one day develop into a glorious butthole (although why we stop calling it the far more awesome sounding "blastopore" is anybody's guess). But in the beginning, you are just an embryonic, unconnected anus floating around in your mom's uterus, which is both the literal truth and a pretty sick burn, if you care to use it.
"Imma whip your coelom-filled, mesoderm-lined ass, bitch!"
The blastopore anus eventually widens like some primitive goatse before tunneling through the blastula until it reaches the other side, where finally the mouth is formed. So essentially, Nature makes humans by constructing two opposing holes and then kind of filling in the blanks. "Deuterostome" is actually a Greek term that means "mouth second," because it's the second part of the body that humans develop, and naming the process any differently would have ended up with us calling ourselves "ass first."