ushills
Veteran
Have you experience to substantiate your comment that there will pretty much always time for your reflexes to work. I have direct experience to the contrary and have been cycling including racing for a very long time. To think you will always be able to brace for impact or take actions to protect yourself is very misguided in general amongst most people. This goes someway to explain risk taking in life in general the misguided feeling of invulnerability.You don't have to expect it though. You don't teleport into the ground or the wall, so there is pretty much always going to be time for your reflexes to work, even if that's in the brief moment that you're flying off your bike towards the ground.
I have had two occasions where my life nearly ended, once on a bike once not and neither time did I have time to do anything. The times I've had accidents before the outcome has never been as bad because I did have some warning, the unexpected collisions are the once that are usually final/fatal.