I have started to respond to this thread numerous times, and either get distracted (and lose my answer) or get babbling on and on about my ridiculously huge wardrobe, and realize that this isn't the place. So I think I'll start my own thread about my own issues, at some point.
So, how much is too much? When you realize there aren't enough days to wear all your clothes. When you realize you have only worn your "favourite" pieces a handful of times.
This is me. In particular when it comes to summer, I appear to really like summer clothes.
No number, as I think a number has so many personal variables. Just reality.
Anchie, your capsule approach is really interesting.