I noticed , when I hit a 'massive' er, 28 mph on my HH7, that the slightest mishap would land me in hospital. (again) See Oldisonfoldies post about hitting fruit with narrow Stelvio tires.

As a kid I went down a steep hill 'speed testing', put the front brake on when a wobble started, and the brake blocks flew out - they'd been fitted backwards. Hit a lamp-post and broke an arm and a collarbone. The bike looked like it had been run over by a train.

Have tried to avoid repeating the experience.

I think potholes and road debris are pretty dangerous, the faster you go, the more difficulty you'll have spotting them, as your vision is necessarily focused much further ahead.