A number of things I did as a kid I'm not especially proud of, including a fair bit of fighting.
One which got our parents worried but wasn't deliberately bad was a day when I had a deadline to get home, and went off with a bunch of mates to do climbing/digging/making horrendously dangerous swings/treehouses etc. I did keep checking my watch, but it was only as it got dark that I realised it probably wasn't four o'clock on a late spring afternoon any more.
Police had been called
Worst injury-related one was an accident with a large knife whereby my good friend Chris Jubb got his finger slashed open to the bone.
Of course, we alerted my parents immedaitely to get him to hospital.
Did we heck! We wrapped it in a handkerchief, he stuffed his hand in his pocket, and left abruptly to go home... His mum did find out, unsurprisingly.
Most embarrassing was the failure of an elaborate cherry-knocking plan, which involved tying a fishing line to the next door knocker, and hiding behind the hedge to repeatedly knock.
Unfortunately for me, there was someone in the hall as I tied the line, who saw my outline in the window and opened the door.
I had to go back and apologise. It wasn't a terribly bad thing to do, but it was deeply embarrassing, and I didn't really speak to those neighbours again. I was still embarrassed about it when I was in the sixth form with the girl next door about five years later.