I find that the older I get, the better I am at imagining how it would feel to hit the pavement at speed (or a guardrail, or a tree).
The bike itself is also a big factor. Strava tells me that I reached my maximum speed on a very stable steel Colnago. I don't ride that bike very often these days, preferring a lighter cf bike that's quicker up hills, but more skittery on the way down.