I am, of course, far too straight to have ever snuck into anything underaged etc.
The only event like that I recall is going to see A Fish Called Wanda with my mum and stepdad at the cinema when I was 13 and it was actually a 15, but obviously no one really cares about this.
However as a kid my best mate and I did a weird period of sneaking around in the gardens behind her house. I guess we were 11ish but honestly not really sure at all. Her flat was at the top of a huge old semi-detached house in Archway with these big gardens behind all the houses
that’s the Google satelite view of the area.
We’d actually sneak out after dark and climb over the fences and go between the gardens. Didn’t really consider how totally dodgy it was until we mentioned it to one of our mum’s and got majorly shut down.
Was fun, though.