Every other horse in the arena is twitching and jumping at the sound of sirens going by, and yours is looking in the direction of the noise with his ears forward and head up, as if thinking "I wonder if I could outrun them?"
You argue with your horse for ten minutes over the proper lead, give up cuing him and hope, and he picks up the proper lead for the rest of the class.
A nip from another horse is met with a slight jump and a dirty glare, not an all-out screaming fit or fight.
You ask and ask and ask for a left sidepass on the fence, and he just doesn't get what you're wanting, but when you try the gate, just because that's what the rest of the class is doing, he performs perfectly.
Your right rein falls off the bit, in the middle of class, while loping, and upon realizing this, your horse responds to your whoa with a beautiful stop, rather than taking advantage of the fact that you only have half control.
It was a long riding class today.