When I turned 17, I jumped from my 5bhp FS1E to a 30 Bhp 250 learner bike (with no lessons or tests except what my dad gave me) which I took my test on almost immediately, and passed. That meant that at 17 yrs and a couple of months old, with very little real bike time, I could jump straight on a Z1000 etc - if I could afford it. I couldn't, but my dad could, BUT he wouldn't give in because he'd grown up with bikes and knew I'd likely kill myself.
To be honest, in the late 70's, my 250 was all I needed. I toured the UK, toured Northern Spain, France, Germany and many other places on that bike and even though I was always wanting & dreaming of more power, I managed without it - and loved my bike, until I was 21 and I eventually got a 650.
I'd have killed to have something like a Fazer 600 at 17 - even with 33 bhp !
Having a son about the same age as ChrisTo, who's ridden his Fazer 600 since a couple of weeks after his 17th birthday, I can actually say the 33bhp rule has Ben good for him. My son got used to riding the bike without full power being available, but also leavened to manoeuvre it in traffic and at low speed - where on our roads today, he still spends most of his time even though the bike now it's full complement of 95bhp.
Having said all that, I also agree with ChrisTo. - being a pilot myself and having just had to sit my annual re-test, I agree it's pretty much an essential and maybe should, in some form, be introduced for all "vehicle" operators.
If nothing else, at least once a year I worry, fret and panic about whether or not I've done enough hours and practiced enough at my "skills" (those which you don't use in everyday flying but are essential should you have a mechanical problem whilst in the air) to still be a capable and competent pilot.
Maybe it wouldn't be too bad if we had something similar to keep our driving licences.
(Now looking to get shot at by all and sundry).