Age is a weird prejudice because it depends so much on environment. In most companies, you're viewed negatively before age 30: you're expected to work the worst hours because the assumption is that you have nothing "better" to do and would just be out drinking. In Silicon Valley, you're viewed negatively after 30. Some doors close and others open.

I do find, strangely, that I'm way more attractive to women now that I'm older, even though my looks have (objectively) declined. Adolescent men are unwanted, invisible, and generally disliked by society unless they're in the top 5% for social skills; things get better at 25 and a lot better after 30... although I'm still glad that I married young because I'd imagine that the dating pool shrinks considerably.