I would think anything after 30. No matter how much work you put into yourself, your health is still declining faster than it was years ago. That moment in time is very confusing for some. Wishing they can relive old glory when in reality, they're just washed up. I've seen plenty of 30+ year olds have breakdowns about their lives and about becoming 40+. It also means they'll need to be shooting their luck at elderly dating sites sometime soon, if they've been stuck on lame ass forums or sites like this without improving anything in their miserable life for years. Literally, just rotting flesh perfect for fertilizer.