Eh, it's standardised quite a lot. As a young adult I had a Triumph Bonneville (still do), small Ducati (went up in flames) and a bunch of Japanese bikes (which lasted varying lengths of time, between dying natural deaths and being slung yp the road).

The point being that the gearchange on the Triumph was 1 up, 3 down on the right, the japanese bikes were 1 down 4 or 5 up on the left and the ducati was 1 down 4 up but on the right hand side. Given the random interchange/pattern between gear and rear brake, the first few miles were always interesting while trying to re-arrange the mental model to fit the current bike.

Which is why, to this day, I really dislike it when new versions of software randomly shift the position of the steering wheel from the usual position to wherever some UX person has decided it should now be (like behind my left ear).

Edit: But to expand on this a little, on a motorbike (or indeed a bicycle), the interface puts everything directly under hand/foot control. Every necessary control is a minor movement, and pretty much the only difference between bike controls these days is the (thumb-based) switch layout