Just to add more variety to the discussion...
There is a genetic propensity on the male side of my father's family to occasionally shorten one's fuse to a nib and become enraged for something less than trivial.
My grandfather dealt with it by driving a school bus for thirty years, and by the time he retired to the family farm was the most charitable and personable man I've ever known.
My uncle dealt with it by having a heart attack in traffic and nearly dying when his car flipped.
My dad dealt with it by having a stroke when I was fourteen, and up until that point was a bomb waiting to go off at all times.
Of course, his rage didn't really go away, it just became more predictable since he could no longer work a full day without a nap, and the closer that nap-time got, the easier he'd be to set off.
I grew up tiptoeing around my dad and bonding with my mom, and it wasn't until age 16 that I stood up to my dad during one of his ragings (this particular time set off by me sitting and listening politely to his side of the argument like he'd asked, then asking that he return the favor for my side), and suddenly felt powerful.
I wasn't into athletics as a boy, more interested in learning amazing things about nature and reading books and playing piano and singing than running with the pack, especially since I was an introvert and both of my parents were musicians and encouraged me to sing solos in church and take piano lessons.
I tended to have exactly one friend at a time instead of a group of running buddies, and pour all my energy into that one friend, but childhood being childhood all of them moved away eventually.
I did get into a lot of fights, mostly because I couldn't let anything anyone said roll off my back.
I didn't have a solid sense of self, and so would lash out, which in recent years I've learned was a tendency that baffled my teachers because my grades were always top-notch and I was always polite and honest with adults, even when I was in trouble.
I wasn't able to deal with my own personal maybe-genetic anger until 7th grade (ironically the one year I actually played school football), when I finally just got pounded into the carpet by a much bigger guy....right in front of the principal's office.
The experience left me conscious of the fact that if I continued to lash out, eventually it would turn deadly, especially with all the drug trafficking and gang violence that happened in my hometown.
So starting at age fifteen, I began reaching out of my introvert-shell.
Especially when, disgruntled with the lackluster state of my school's mixed choir and still singing in my falsetto (even with a basso profundo speaking voice), I asked to be able to audition for the girls' choir, which was made up of a large number of girls I'd grown up with and several of whom had taken or were taking private voice lessons.
So I sang soprano at the end of junior high, and the quirkiness of the situation led several of my fellow choristers to open up to me as I'd never experienced before, being the introvert with a book in the corner all through elementary school.
I was neck-deep in the friendzone, but I didn't care at the time because I was getting female attention and actually forming some friendships which lasted through college.
As a result of that initial reaching, I started a process to grow into an other-end-of-the-spectrum extrovert, which has stayed with me.
I'm still not into athletics for the most part, though I enjoy watching football enough that I can be sociable at a party with a game on.
I've never been hunting, I've barely fired a weapon (thus my insecurity following this past Christmas), I was a virgin until 17, I've never killed a man or beast big enough to threaten me.......and I'm more likely to try to talk my way out of a fight than bumrush somebody.
I've personally never understood the idea of "manliness," especially since our culture long ago abandoned any standard rites for entering adulthood.
All we have now is basically "Well, you're x-age, you'd better do x-thing," which is just "you have the legal right to do so now, so you should consider it," whether it's driving, buying cigarettes, enlisting in the military, drinking alcohol, or renting a car.
So since we have no clear understanding (as opposed to cultures which have very clear demarcation lines between childhood and adulthood), how can we agree on any ideas of "masculinity," or should we, especially when the more barbaric gender roles for males (hunting, killing, frequently mating) are gradually and rightfully being abandoned in favor of an egalitarian system?
As a t-shirt I saw awhile back put it:
EDIT: On an unrelated note, this thread title has the theme from "Two and a Half Men" stuck in my head.