How long until new acquisitions become "Just part of the rotation"?

[vaulter1]

I'm not a flipper of watches but have a small, modest collection. I usually rotate through a few of them over the course of the week but having recently picked up a lovely 16710 the rest have stayed in the box. I'm sure I'll get back to the rotation eventually but I'm curious if anyone else around here has experienced the same when adding to their collection.