Because when you die, no one will ever know to care. You didn't have any impact on their lives and you never left any impression for people to remember you by. You're only being acknowledged because you were standing beside the woman you married, and it's because people were calling out to her, so they gave you a nod or a wave or a "hi" as only a stranger's courtesy. And that's exactly what it means, like a hand sign when you're in car and someone's on the opposite lane trying to cross into a junction, and you were trying to be kind to let them pass, but to them it doesn't mean anything more so all you get is a hand sign, and 15 minutes later they would have forgotten your gesture or your face. That kind of stranger courtesy, face to face. As minimal interaction as possible with them, that's where you are in the social scene. But you're already used to it when you were young, this was nothing new. You're not upset your wife is getting the attention and you're cast aside, you're more upset at the fact that you've been experiencing this since you were young. And you tried to do something about it, to try to change, but nothing's changed. You try to be kind to strangers but it's not gonna leave a mark on them, so it's not gonna affect you in any way. You try to be nice and put in the effort for your friends, put a smile on your face and try to talk to them when you're hanging out even when your mind is wasting away somewhere else, but after a while nobody cares about you. Some even make fun of your stuttering.  So you're always at the side of a conversation and you tried so hard to join in, but if they do focus on you, you couldn't keep it up for 2 minutes before they start looking elsewhere. Being ignored. To be invisible. To blend into wallpaper. So now you don't want to feel pathetic and have people laughing at you, so you decided to make it where this is part of your character. You take that HURT as brick and mortar for your wall so people will feel it's difficult and distant to approach you. And it becomes a never ending cycle. You take the trauma that is being accumulated and compounded year over year, and you inject it back to the same vein over and over again, until finally the person says enough is enough! And that's when nobody knows how this is gonna end.