They used to call it “Run what you Brung.”
I can’t tell you how many times I hear or read that someone can’t do a particular ride because they don’t have the right bike (this goes for MTB too). Seriously? I mean Seriously?!
Just get out there and ride. Sure, you’re not going to take your Fat Boy on a Motocross track or anything (or…see below) but most of the time, if you have a bike you could be riding it.

I ride my Dorsoduro on the track, to commute, on gravel roads and even the occasional double track, all with a set of Dunlop Q3s. I’m lucky enough to have a spare set of wheels that I put some TKCs on and have greatly increased it’s off-road worthiness and plan to explore even more now.
So that’s another point I want to make, small changes to the bike you already have can make it more versatile. Riser bars, different tires, lower or high gearing, all small changes that can have a big impact on how capable your bike is in different situations.
I’m starting to think that all those Forum Jockeys with their Garage Queens are doing nothing but spending time and money on bling that adds nothing to their riding experience and posting pictures of their precious all day is mostly because they don’t or can’t fuckin’ ride!
My RSV4 didn’t pass sound inspection at a trackday last year (imagine that!). What did I do? I drove home over an hour and half and picked up the trusty Dorsoduro, then drove an hour plus back to the track. I still got in a day and a half of riding with my buddies. Sure their 1000cc bikes blew my doors off on the straights, but I kept up with a lot of them through the corners. See it here:
Thing is I rode. I learned some things riding a slower bike, and I had a hell of a lot of fun. I did that all with the WRONG bike, if there is such a thing.
Go Ride!