Just a friendly bit of constructive criticism: pain is reading a 1500 word essay with no paragraphs. Ouch.
Pain. I like pain. It lets you know you're still living, as my father used to say. He also said ,"what does not kill you, will only make you stronger."
I listen to what my body is telling me. Pain that says there is damage means I need to slow down and let things heal. Pain in technique that warns of impending injury I will take note of and either allow to go on a bit longer or put a stop to by tapping. Yes I like the endorphins but not enough to wish to be damaged to the point I won't be training for a while.
If I tap out as soon as there is pain I can't study the pain and see how I might counter someone who is applying it.
And as to the jumping out of bed in the morning and feeling no pain. Well if you do that's great. But not every one is so lucky. I've lived a busy life and my body reminds me of it every day. And I'm not even out of my 30's yet. Like I said. Pain just reminds us we're still living. Not always enjoyable but not necessarily unwelcome either.