I don't know how much we can go with canon, since most long-running characters have been depicted in various or even contradictory ways. And many will never get this old in canon.

But today I was thinking out which ones would reflect on the round number birthdays and how they'd feel about it. Obviously, a huge number of people in the real world don't care about those birthdays, but some do. I know a few people who were bothered by 30, but fine with 40, etc.

I was thinking that if Dick wasn't married and didn't have a job and ordinary-life direction at 30, it might bother him. This is definitely referencing an older version of Dick Grayson, but that's the one I like.

In my head, Ralph Dibny is thrilled at 30. Everything in life is just what he wants it to be, he's happy and fulfilled and ready for the next phase, as it were. Of course, I also don't kill off him or his wife, so they are happy for ever after. Very fond of their pre-COIE dynamic.

I could see both Bruce and Selina less than thrilled with 50, but it depends on what their lives are like, of course. For Bruce, it's an age where if he isn't retired, he has to know it has to come soon (or that he'll die in action soon). While still exceptional, he'd be well past his own peak/plateau and definitely declining. It's the end of being able to do this job or a time when he reflects on the job done. So, what does Gotham look like? Selina, on the other hand, I think would accept retirement easily. But societally, we put a lot of value on a woman's youth and sex appeal. She wouldn't have been young for a long while then, but there does seem to be some nebulous point where the bulk of the under 30s just don't see sex appeal in a person (a few famous ones excepted) and I wonder if that would bother her.

Donna, I feel, would be very dependent on on her life circumstance. The age alone would not be a turning point to have an impact. It's all in how her life is going, and I think she wouldn't even notice the birthday if her life was happy at the time. Alas, with DC it's likely to be going miserably. I have a happier headcanon that will never be.

I could see 40 bothering Ted. The point when he's indisputably no longer young. He's middle-aged, even. I know a lot of people use 45, and some will even say 50, but I just don't agree with that, and while we may get off on a tangent about where those lines are drawn and if they vary person to person, but for the moment, let's just say I think Ted thinks this way.