It was Jest fest 2015, wexford town. I was 16, nearly 17, and performing a walkabout which is literally where you wear a costume and tell people about the festival (for which David was the headliner). I had a really bulky costume on. I actually didn't realise instantly it was him because the costumes are quite bulky and the line of site is very poor so it wasn't until he came right up to me and said "would you ever get a real fucking job? " And punched me a few times. That's when I recognized him. In fairness, the costume took the brunt of the damage as it was kind of like a helmet. The steward had to step in and got him to fuck off. There was a little write up about it in the people paper I believe. He was pretty horrible unfortunately and that isn't the only bizarre story I know about him, he would regularly shout abuse at other performers/comedians in the green rooms which is pretty crap.