When I was in grade 2, age 7. That time we moved to a different city. I used to love it in those times because I thought people are laughing "with" me, so, I must be humorous in some way. As I grew up, I realised they are actually laughing "at" me. I still continue to stammer, and intentionally add elements of humour around the words that I am confident I will stammer. It's like shadowing my stammer while others are busy laughing, lol.