I've done some regrettable things for sure, but like you, no consequences ever came to pass. Do I sometimes cringe when I think about the possible consequences? Hell yea, but there's still nothing to regret.
The things I really and sometimes painfully regret are the things I didn't do when I had the chance.
Some of the things that make me cringe are all similar to yours. There was the time I drove home from South San Jose to Oakland (about 60 miles/96 km) belligerently double vision drunk on tequila after brawling with my friends who were in the same condition. I was aware of the consequences so I took precautions. I closed one eye cuz I had to in order to see straight and I set my cruise control for 55 mph. Yes that's how long ago it was. The speed limit was still 55 mph. The whole time scheming about my revenge LOL of course we all forgave and forgot within the month.
Then there was a time I was half drunk off about six or seven beers and racing my friend from the bar to the union hall for a meeting. I had him beat but then he didn't illegal pass on me, which caused me to break traction at the stop sign that I didn't stop at to pass him in the same illegal fashion across the double yellow. When I looked in my rearview mirror to see his expression, imagine my surprise went instead I saw the blue and red lights of the police car that was chasing me down. My first thought was to outrun him, but I came to my senses within a couple blocks and pulled over right in front of the hall and watch my friend drive by with a look of sorrow and horror on his face. We both thought I was about to lose everything. The cop had been following us since he did his illegal pass on me and I didn't notice but what I did was way worse than what he did so the cop just forgot about him and focused on me which was good for my friend because he would have gone down for sure. The cop asked me for my license and registration which I was in the middle of sorting out when he walked up. Then he walked back to check my plate which is a personalized veterans plate with my rank on it. He came back and give me a verbal warning shook his finger and told me to knock it off and be safe. I thanked him and went on my way. When I got into the meeting, my friend already had a small gathering of a few of our mutual friends, telling them about all the beer we just drank in about how I'm going down. I tapped him on his shoulder and when he turned around and saw me it was like he saw a ghost. It was hilarious. When I think about it, I think me outrageously breaking all those traffic laws is what saved us both because originally the cop was going to pull us both over for speeding and him for the illegal pass. And I think if he would have pulled us both over he might not have given me a break because he would have had for sure taking my friend in. He had no registration, no license (because of DUIs), no insurance, and the back of his truck was full of empty beer cans. I don't think the cop ever noticed that I had been drinking, but he would have noticed then for sure.
This next one still gives me nightmares. I drove home from a rave in San Francisco to Oakland, Frying on a puddle of liquid acid. I remember I stopped on Treasure Island for a breather and I don't know if I was there for an hour or a minute but I know it was still dark when I left and still dark when I got home My nightmares are about me driving and getting sidetracked doing something else, and forgetting that I'm still driving. I didn't mean to do so much acid that night. But it was dark and my buddy was Dripping it into my hand out of a Visine bottle . Neither of us could see how much he had dropped into my palm. When I put my Palms in my mouth that's when the light caught the puddle, and it was a puddle, but by the time that all registered, it was already down the hatch. I have never fried so hard and I've never fried since.