The phrase "tap out" has slid into the mainstream over the last 25 years or so, but its original meaning has been forgotten, or at least misinterpreted. When you're training Brazilian Jiu Jitsu, one of the most important things you can do is tap.
It's a fundamental part of the learning experience. In class, you'll tap over and over again as you figure out what not to do. Tapping out isn't seen as quitting and it's not a sign of admitting defeat. It's a way of saying, "Yep, you got me. Let's go again and see what happens."
Tapping is also an ego-check. Think you're "too hardcore" to tap when you end up in a bad position? It's amazing how much humble pie you're able to eat when someone's radius is crushing your carotid artery.
Okay, buddy, enjoy your nap. When you wake up, go research "Judo Gene LeBell and Steven Seagal", see what kind of company you're in, and then come back to class with a better attitude (and maybe a new pair of pants).
Show me an elite fighter who's never tapped. They simply don't exist. The most dangerous bad-asses on the planet tap out regularly in training because they know that's how you get better. If you're practicing and never need to tap, it doesn't mean you're an indomitable beast. It means you're surrounded by less-skilled weaklings who don't challenge you and you'll end up a paper tiger.
This ties back to mental toughness. People with real grit understand that true success only comes from repeatedly recognizing when you've made a wrong turn, owning up to the situation, and then doggedly getting back to work again and again and again.
The (unacceptable) alternative is to be the type of person who hits one obstacle, sees it as insurmountable, and decides reaching the goal isn't worth a little bit of uncomfortable work.