When I play at home everything is perfect. The stand is in the right place and the lighting is just right. The heat is on. I warmed up properly and play. In the real world there isn't enough room for the stand so it's not placed properly. The guy in front of me is blocking my view of the conductor. (maybe a good thing?) The room is cold. I couldn't warm up properly or I did and now it's been a long time. Tacit for the first two movements. I have to play the last movement and it's long with nowhere to even breath never mind take the trumpet away for a rest. Shouldn't we practice how we play?