EGKB, people are being pretty hard on you now
might be better to duck out
.
Ease up a little people he really has chilled out and seen the error of his ways and understand that instructors have to start somewhere.
Also, I am deadly serious. The bit that people take the longest to master is unquestionably straight and level. So many things can happen to disturb it and you're always busy trying to make sure you're in the right place or on the right track. You're rarely flying with the ball in the middle which means you're not tracking straight towards stuff, the power isn't quite right, the trim isn't quite right. Straight and Level is difficult because your aircraft changes height and heading without being obvious and you'll often find yourself trying to stay straight and level for long periods. It doesn't change when you get into an airliner (that doesn't have fancy things like AP and AT and AutoTrim).
Trust me, your instructor will be driving you bonkers with calls of "heading" "altitude"
.
Good luck.