I've had a couple startles this year with black snakes, one was hidden in the top of my barn door and when I opened it he fell down right in front of me and nearly gave me a heart attack. I can only imagine if he had actually fallen on me, that would have been even worse. Since then I look carefully before opening the door and one other time I saw a real little snake peeking out and was prepared.
Then another time, I had randomly stacked a few 16" patio paver blocks on some lumber, and when I picked up a block I found a snake had crawled under there. Both of us freaked out and of course I dropped the block, which pinned the snake in place with his upper body able to still lash out at me. He was not happy about that and was not making it easy for me to lift the block back off. But I finally got in there quick and he took off with a bit of a kink in his body, hopefully he's OK as I like having black snakes around.
Last week my wife shouts out "there's a copperhead by the front door" when she was taking the dog out, so I rush around the corner to see a real fat snake that was definitely not a copperhead and was probably a juvenile black snake that hadn't turned black yet. I shooed him off since I thought for sure he'd give someone a startle. I like having these beneficial snakes around, but with copperheads and water moccasins also on our property, we have to be vigilant and I like to get a positive ID anytime I see a snake. If it's a bad guy the shovel or shotgun comes out. Since we have a small child, the shotgun is locked away and not easily accessible, which makes it less useful.