How many bikes is it right to own?

I've been considering this recently, and I don't know.

1. I'd keep my fixie-wixie
   
2. and my new audax affair
   
3. eventually it'd be fun to own a dura-ace equipped racing bike
   
4. and probably a rigid or hardtail singlespeed mountain bike
   
5. and an all-singing, all-dancing full bouncer of some kind
   
   

So... 5. But that's how many I'd like to own, not how many is 'right'. Personally I don't see the problem; They'd still take up less space than a car.