With Steve, I always viewed it that he probably had been in love before and he probably did have a lady, maybe even had a family, and lost that to this awful conflict. The thought of falling in love is so painful for him that he could not allow himself to do it. It had to be about a mission, it had to be God and country, but it could not be him and what he wanted. He’s got a mission that, up until the very last, is his driving force. Along the way he happens to fall madly in love with a goddess. And he just holds off and holds off and holds off until he can’t bear to let her go.
Chris Pine, on Steve Trevor in Wonder Woman: The Art And Making Of The Film