Hi,
Not so much 'collect' as 'accumulate'. I've had a fascination for plugs & sockets since my childhood. (I wonder what Freud would make of it?)
When we moved here to France, a big box of 'Bakelitery' came with us.
I've used some 15 amp fittings for the oven & water heater as I didn't have any French stuff handy when I installed them.
I use 2 amp fittings for speakers, which is more convenient than those spring things on the back of my PA equipment.
Cheers, Pete.