I've had so many, I can't count them. I was bowhunting back when we had the week of archery between ml and gun in November. I was hunting with a Martin with double hatchet cams. What was back then a really nice 8 point sneaked in right beside my stand. Less than 10 yards. I managed to get stood up, bow in hand, turned around in position to shoot without scaring him. He was broadside, licking his shoulder so that his head was hid from me - PERFECT! I went to draw my bow that cold November morning and in my cold state, I could not break the cams over the hump. I pulled and pulled. I finally pointed the bow up toward the heavens and drew one last time - the arrow fell off the rest, the buck took off like a bullet and was gone! Sold that bow and bought a Mathews the next season.
One morning during ML season, it was drizzling the rain. I had put a percussion cap on my American Knight ML once I was up in my tree. I was watching a squirrel on the ground, when all at once, he ran up a small tree - hanging upside down, he started looking out the ridge, wagging his tail. I watched the same direction he was watching and sure enough, here came the biggest buck I'd ever seen in the woods at that time in my life. He was trotting like he was on the scent of a doe. He made it about 80 yards from me and cut down in the holler and disappeared. I pulled out my can call and hit a few times. In a couple of minutes, he came back up on the ridge and straight to me, stopped about 40 yards broadside....just like he'd read the script. I put my crosshairs on him and pulled the trigger - SNAP! HUH??? I looked down - no percussion cap!! It had fallen off. Normally, I have one right at hand, but since it was raining, I had stuck them in a pocket. But, in my nervous state, I couldn't remember what pocket! He got nervous and took off running. Never saw him again. I was sick.
These are but the tip of the iceberg! I've often thought about, and even started one time - writing a book about these type experiences and the hunting lessons I learned and the life lessons I've learned. Maybe someday.