I really have never carried one. I prefer my knives to be sharp and to stay that way under use. But I've supplied my wife with several over the years. Maybe the most memorable is the one with a thumb drive as one of the instruments. She uses the tooth pick and tweezers frequently.
But the best story is about my oldest son who will turn 45 this summer. Way back in his youth he saved his money. All of it for a long time (its relative for kids). And about the time he was either 9 or 10, I forget which, I noticed he hadn't spent his birthday money either. Something was up. I just figured I'd learn in due time. So that fall we went to the Smokey Mountains for a weekend. And as was our habit, we stayed in Gatlinburg. And the son had his stash along with him, having counted it a few dozen times. He was going to the Acorn shop, a knife shop down in the center of town. Guess it was convenient to bring mom and dad along in case they were needed for the purchase. Surprisingly, he had a real good idea which SAK he wanted, and knew about how much they cost. Yes, he had more than enough money.
So he took his prized knife home and had it with him pretty much. Then about his 14th year, we lost track of it. At least we stopped seeing it. So more time passed and we pretty much all forgot about it. I figured he got his money's worth out of the darn thing.
Time passed and we were moving out of the old house. His room was basically undisturbed (a disaster). So we summoned him home to clean it out, taking what he wanted and throwing the rest away. So digging his way in he started yelling. He found his knife! It was in a box full of toy rocket stuff. I don't know what happened to that junk, but the knife went into his pocket. I've asked him about it a few time over the last 20 years, and he's got it in his safe. I'm guessing he won't be giving it to any of his kids - too valuable. If they want one, let them buy their own!