That
"It works better if you get ON it!"
The looks of joy on their faces! 
I live in a block of flats with a huge communal garden. DD's trampoline is right outside my kitchen window and I encourage ALL the children to use it and the adults
I could hear them saying 'but we don't know whose it is, someone might shout at us!'
So I said the above and told them it was mine
Can now hear squeals of joy!
Their dad came over and told them to get off
So I stuck head out of window and told him it was mine and I was fine with it. Told him to have a go too!
And HE DID!
The roars of laughter from these two small children as Dad had the time of his life will stay with me for a long time.
That trampoline is now a very happy trampoline
I rang DD and told her and she laughed too!
So. Was I BU?