Heisenberg states that you can't know the exact position and exact velocity of the same particle at the same time. It's even possible to quantify this exclusion, to describe the balance between the two properties. What it comes down to, though, is that the more precisely you define one thing, the less precisely you can define the other.
Here are some facts about Tony Stark:
He is an engineering student at MIT. The best in his class, in fact the best in every class he takes. He is a genius, a prodigy, a bit of a geek and yet also a bit of a playboy.
He goes on a lot of dates with a lot of girls. Some of them make claims afterward about what happened on those dates, but Tony shrugs and smiles and refuses to kiss and tell.
He is a boy in the process of becoming a man, and the process is almost—but never quite—finished.
When he meets Jim Rhodes, he doesn't notice at first.
At first it's just a friendship like any other. At first it's comfortable, natural. At first there's nothing wrong.
And then, one day that should have been just like any other day, Tony catches sight of Rhodey across the street and sees something there, something in the line of his body as he turns back to wave to a friend through the layered glass of a revolving door. He recognizes it immediately—the way it feels like his heart just skipped a beat, even though he's pretty sure hearts don't actually do that—and in the next second he tries to erase the knowledge from his mind. That's not him. That didn't just happen. He's not into guys. He'd never look at his buddy like that. No, no, no, and no.
He can feel the way he draws in on himself, a silent implosion of confidence. His feet slide closer together and his weight shifts and his spine curves and, perfectly aware that he is standing like a girl—a shy girl—he flees, not caring in that moment who might see him running and wonder why.
He doesn't run like a girl, at least.
There is a full-length mirror in Tony's bedroom. "My name is Anthony Edward Stark," he tells it. It doesn't help. He undresses and spends a long time staring into his own eyes, ignoring everything else the mirror shows. Ignoring it very self-consciously. That doesn't help either.
Anthony Edward Stark. Anthony Edward Stark. Anthony Edward Stark. Anthony Edward Stark. Anthony—Edward—Stark.
At the point where his name is a meaningless sequence of sounds and he still doesn't feel comfortable in his own skin, Tony gives up and goes to bed. His chest aches. He sleeps on his back with his head turned to the side so he can still breathe under the pillow.
He hopes it won't happen again, but it does. He hides behind textbooks and equations and booze and girls and everything he can think of to put between himself and this thing that's happening to him. Rhodey is oblivious. If Tony laughs a little too loud sometimes, looks at him too intently or looks away too fast, well, nobody's ever expected Tony Stark to be normal. Standard rules don't apply.
Tony has been secure in his masculinity ever since he knew he had it. Not a moment's doubt, not a moment's pause. He wonders now if that was a mistake, and he hates wondering, and he cringes inside when Rhodey gives him a playful shove that comes a little too close to one of the twin surgical scars hidden under his shirt. Rhodey, good old Rhodey, asks if something's wrong and accepts Tony's dismissive not-even-worth-explaining-it wave as an answer. Tony loves him a little more for it.
That night, he has no conversations with the mirror. He lies awake in the dark, staring at the ceiling, refusing to look at the clock and discover how many hours past midnight this train of thought has taken him. Is he gay? Is that what this is? He likes girls. He thinks he likes girls. He thinks he's a guy, too, and look where that's gotten him. Fuck.
No. He's a guy, and he's straight, and he just... got his wires crossed somehow, that's all. It's a fluke. It's nothing. It doesn't mean anything. There's no problem.
Yeah, that line doesn't really work.
There are dreams, of course. Dreams of kissing, dreams of other things. Dreams of floating weightless in space, surrounded by an ocean of stars, holding hands. If Tony didn't feel like a fucking girl before that last, he sure as hell does now.
Once, he dreams of jerking off to a photo of Rhodey's smile. The smile is real; the photo is not. When he wakes up, for a long moment he's too disgusted to throw off the blanket and remind himself what isn't there.
Once he dreams that Rhodey is a woman, and when he takes her shirt off he finds two lumps of fleshy plastic—a brown too pale to match her skin—that peel away from her chest and fall, revealing familiar scars. He doesn't know what the fuck to think about that one.
If he drinks enough, he's too hung over in the morning to remember what he dreamed.
Nothing really changes. There's no epiphany, no moment where it all comes together again like it did the first time. His crush on his best friend never goes anywhere, including away.
It's just that—just exactly that: nothing changes. For all his insecurities, all his late nights and later mornings, all his time in front of the mirror, he keeps going. And gradually, he starts believing again in what he always knew before: that he, Tony Stark, knows exactly where he is and exactly where he's going.
Fuck uncertainty anyway.