You can never have too many bikes, I used to take my trials bike out when my youngest son had just learned to ride a bike. Went to a local factory car park which was empty and he'd play pretending the barriers were his den and I'd spend my time hopping up the walls and bollards there.
I think since I started riding again 6-7 years ago I've only had one brief period where I've only had one trials bike, nice to have a variety of riding styles be it mod, stock or 24 though it can be a nightmare switching between them. I had a ride out years ago on one of my 26's then swapped it for my 20, went down the road to a wall I could easily hop up, went for it and just ploughed head on ending in a heap on the floor cause it needed a totally different technique to lift the front end up!
A women stood at the bus stop next to me just stood there pissing herself!