There are so many characters in comics, who are and always were in their prime and you know that they won't get past that. Wolverine is such an example I think. We know that he got older, but he was always Wolverine as we know him. The same applies for Batman, even though he had his Year One stories. Captain America is another example, then there is also Bruce Banner / Hulk and so on. The same applies for villains. Look at Catwoman, Green Goblin, Mr. Freeze and many others.
I would say Spider-Man, who gained his powers, when he was 15 and now he is much older. Also Nightwing, Red Hood and Red Robin. But Red Robin didn't make the same jump as the two others. I think that Damian will always stay a little kid.