Does age matter?

Fighting is a hard and dangerous sport. It wears down and hurts your body over time, just like boxing. When a fighter is young it is easier to heal faster and become stronger, but what about when you age?
Is it harder to get better and stronger when you are injured?I think it is. I believe there should be an age limit of the UFC. I think if you are older than 35 you shouldn't be able to fight. I think that is a good age to stop. There are fighters who are older than 40 and still fight, like Randy Couture and he was a heavy weight champion. I'm not saying you can't still be a good fighter at that age, but you might not realize it at the time but you are damaging you body more than you did in your 20's.
My favorite fighter is Matt Hughes, as I have mentioned before, and he is now 35 years old. Even though I love watching him fight, he has gotten slower, and less agressive. I think he wears his body out and it can't take that anymore. I think he should stop while he is still considered a great fighter. I know most fighters fight for the love of the sport and they don't want to quit it, but they have to realize that the older they get, the longer it takes to gain strength back. 35 years old should be the limit of age in my opinion.
Plus another reason for having an age limit is maybe people get tired of seeing you if you have lost your skill or talent. The older you get, the less you can do. Like i said, Matt has lost his agressivness and that was his signature skill.
I think age does matter in this sport or maybe any sport. It isn't always safe and healthy for them to continue fighting while they are in their late 30's and early 40's.

Do you think age matters?