Yaw and pitch are like longitude and latitude. Pitch=0 is the equator. Pitch= +90 and -90 are the poles.
Start at the equator, going north. Continue for 135 degrees. You go through the pole and "back down the other side". But you don't say the resulting location has latitude 135. It is 45, and the longitude changes by 180.
Start at the equator, going north. Continue for 135 degrees. You go through the pole and "back down the other side". But you don't say the resulting location has latitude 135. It is 45, and the longitude changes by 180.