I play the violin, but not very well -- and not very often

I got to play viola at music camp a few years ago and that was really fun. Oh, and one time I got to be concertmaster (first and I'm sure only time in my life). It was at music camp and there was a small orchestra. There were only about three violins, so two clarinetists joined the violin section. We were playing this really simple Haydn movement, and my stand partner was this 11-year old boy who was quite brilliant at the violin. So, during rehearsals, he was the concertmaster...but there was one spot where he always came in two bars early after a rest...because it sounded like the right place for the theme to enter. (The theme did enter then, but the flutes or someone had it). I, on the other hand, although a much poorer player, know how to count, so the conductor made me concertmaster for our performance. It was fun...although I felt like a fraud in that chair...