Like others have said, it's not really an 'unlearn/relearn' thing, it's more of a '
learn another way to have fun/enjoy the ride' thing.
I swap the number of wheels I'm piloting frequently, not even restricting myself to just 2 or 3 wheels, I regularly run 6, 8,10, 18, or more wheels, even occasionally up to as many as 66 or so, +8 spares (altho I must admit, my road train driving days are mainly historical now, and tend to be more 'hysterical' than anything else these days; and I'm not all that keen on riding on just ONE wheel, altho the Grandkids think it's great fun to watch me make a fool of myself that way; and right at this moment, with my right foot in a splint since yesterday, but not due to any one-wheel riding, I'm on stoppage of them all for at least a week or two!

)
I'd say that riding a Spyder is more like riding a snow-mobile or a jet-ski than riding a motorbike, but again, as others have said, once you come to grips with it and start really enjoying the ride, there's no more to swapping from your Spyder to a 2-wheeler than there is between swapping from your car to your bike, trike, jet-ski, or snow-mobile! The hum an brain is a wonderful thing, and even when it's been blasted into submission more'n once, if you work at it hard enough, there's a good chance the in-built neuro-plasticity will kick in to let you do a whole lotta things the medical world deemed impossible until it was done!! And just between you'n me, swapping between a Spyder and a 2-wheeler isn't anywhere near as hard as learning to walk again!
Mind you, in a 4 or more wheeler, I still occasionally find myself reaching for another gear or double de-clutching when I don't have one &/or need to; but funnily enough, after the first few weeks of Spyder riding, I haven't reached for the front brake or the clutch on one since, and I've never forgotten to use them on a 2-wheeler either... Go figure?!
