Why do most people wear wristwatches on their left hand?

Why do most people wear wristwatches on their left hand?

Ever since the days of the pocket watch, the stem (the round part you wind) has been placed adjacent to the '3' (on the right-hand side of the watch). This location makes it awkward to wind the clock with the left hand, whether you are left-handed, right-handed or ambidextrous.