The most common end user mistake on a bicycle occurs when they replace pedals. Pedals are NOT righty tighty lefty loosy. End consumers often mess this up. Pedals have a R and L designation for right and left. Right is the drive side and left is the non drive side.

Both pedals tighten towards the front of the bike, and loosen towards the back. Therefore the drive side pedal uses standard threads. However the non-drive side is inverted. End consumers often strip the left crank. Be careful with pedals. No company will warranty striped threads on a non-drive side crank.