I've had a few. I don't like to think about them.
I know what you mean. Scarey.
In jr high i hiked a couple miles from town in south Texas brush country to hunt an oak timbered draw for squirrels in spring.
Stepped up to an oak and a freaking huge 5 foot rattler "jumped" out from the roots around the tree 2 feet away and was so pissed it was unreal. Ive never heard a snake buzz like that before or since, and ive heard many.
I was afraid to move my feet as it was raired back and ready to nail any movement. By the grace of GOD my 22 cal pellet caught it between the eyes.
A few minutes later i put the butt on its head and cut it off. The stump flew back and knocked heck out of the side of my foot, leaving a quarter sized blood stamp on the side of my off white tennis shoe.
No way i would have made it back to town.