In school (I was 10 years old) I sat at the end of a table of 7. So 3 kids either side and I'm the 7th on the end. Bloody loved swinging on my chair. Could never understand why my teacher gave me a row for it, it was so much fun 
Until one day....yep, you know where this is going!
Enjoying my usual swing and balance on the back 2 chair legs... but something went wrong... before I knew it I went flying back and in my panic at trying to stop myself I grabbed onto my desk... but momentum was too great and I took the table with me!!
The whole class immediately turned round to see what the hell all the commotion was and there I was, lying on my back, still sitting in my chair with my legs in the air, trapped under my table!
Nowhere near as embarrassing as the others, but it's one that still makes me roll my eyes and shake my head at myself.
Also aged 10, I woke up late for school one day so had to quickly dress in the previous days clothes and run to school. To my horror, the day before's underwear (which I could've sworn I had put in the laundry) had worked it's way down my trouser leg and made an appearance as I walk across the classroom. Bloody hated being 10,that was not a good year for me 😂
Age 11, me and a friend were walking about after school when we noticed the cabin where our local radio was broadcast.
Now, I'd always fancied myself as a popstar so I convinced my friend to go with me to the cabin.
In we walked, up to the reception desk and said to the lovely lady "I want to be a popstar". She was so nice, told us to wait there while she quickly nipped out the room.
When she came back she was so excited and said "follow me, you're gonna be on air!".
I was so excited!! I was actually going to be a popstar!! Me and my friend ran through the little cabin following the lady into a little room with 2 men at a table with microphones and another man at a table with some technical equipment.
One of the men spoke into the mic, asked me to introduce myself and told the world I wanted to sing.
This is when i lost my bottle and in my embarrassment blurted out a silly made up kiddie rap verse someone told me at school. We were all pretty stunned by the end and there was no doubt we all realised I was not going to be a popstar.
Unfortunately my adventure didn't end there. One of the men started sniffing the air and asked if anyone else could smell something fowel. We all checked our feet... turned out I had dragged dog shit... lots of it... all through the cabin 