One quick way to get me to lose whatever respect I have for you is to utter the phrase "no regrets." If someone above the age of 7 looks back at his life and is sure he wouldn't change the way he did anything, he's either lying to himself or is actually Joe Montana in disguise.
The fact is we all make mistakes. You're making one right now by reading this instead of doing something more productive with your time. And if you refuse to acknowledge the errors, at least in your own mind, and act differently in the future, then you may as well die right now because you're only going to continue behaving in the same idiotic manner until you're invited to the proverbial great tea party in the sky with Jack Ruby and Hunter S. Thompson.
The next time someone tells me they have no regrets, I'll respond "Oh, really? What about failing to complete the fourth grade?" They'll respond indignantly that they did pass fourth grade, and that's when I'll catch them in their lie. See, anyone who's been to fourth grade has wasted valuable paste-eating time picking their nose while paging through "Where's Waldo" books, and thus of course regrets it.
Stunned at the moment of self-reflection, my adversary will instantly convert to my way of thinking and probably offer a large sum of money for the lesson I've just given them.
Should they insist they were happy with their booger-picking "Where's Waldo" reading, I'll punch them in the mouth. After I use smelling salts to revive them from the knockouts, I'll ask them if they have any regrets now, as in regretting they talked to me, which led to their getting punched in the mouth. The question, of course, will be rhetorical. Unless the guy I'm talking to is Joe Montana, whom I'd have no chance against in a fight.