How many CD/LPs do you need?

I intend to build the biggest collection I can.
I've enjoyed watching it grow.
I do recycle CD's for two reasons.
One if a better remaster comes out or if I consider it a donkey with no reedeming features-this only happens occassionaly.
I am quite happy to keep a CD with even only one good track.
I tell you why I probably do this,when I was younger and at college and skint I sold off a lot of vinyl-it left a gap in my collection I could never quite replace.
I regreted it a lot and still do-it's the equivalent of selling your memories-thankfully now I've probably replaced most of it.
Ok it would take me years to work through every CD I have but if I want and I do this often, I have a look through things I haven't played for a while and give it a blast.
Anyway it's great after a major upgrade to hear lots of different stuff through your system.
And hopefully when I pass onto the next place I'll have left behind a collection for someone to enjoy.

I do view my collection like a library-Garfish is right to point out this can indeed be a motivation in itself-I would be deluding myself if I didn't recognise this failing but many a happy mistake has been made or a grateful nod to a record I had ignored but wanted to listen to due to reading something or a recommendation by someone.........more I need more.........