If there is one thing that playing the trumpet taught me, it was confidence.but putting them in a practical exam for a tuba player who is a bit shy (yeah, I know, seems unlikely)
At school a second violinist once said to me "you played that wrong AGAIN". I replied "At least I KNOW when I play something wrong. No-one knows if you are playing at all..". One of the few zingers I've ever come up with quickly...
FYI it was one of those awful movements where the composer has decided they want a brass blast of 1 note in the middle of 400 odd bars of music, and if the conductor fails to wave at you at the right time it's very easy to miss it.