Why do people wear wristwatch on left hands

Even as a lefty ('left handler'), I normally wear wristwatch on my left hand which is a norm I grew up with and loved.

However, lately during my professional exams I had to transfer my watch to my right to enable me to keep writing while still recurrently looking at my watch for timing purpose.

When it was on my left I had to pause the writing and look at the time. You might want to suggest putting the watch on the table, but that's not the point and again it was convenient having the watch on.

At the end of the exam, I questioned the norm (why do I and most people wear wristwatches on the left) and then the answer to the question came quickly.

It occur to me that before things (acts) becomes norms (in a civilized environment) they mostly will have passed "Logical reasoning " then it continues for years and then the generation that did the thinking goes and the new generation just continue it, making "norm" to replace "reason for" and sometimes even turn to fashion.

Back to my topic, Majority of people are right handed and it is easier for them to engage the right hand full time and then the "less-busy" hand has the watch to keep them time conscious.

So I reasonably decided to now wear my watch on my right, it seems inconvenient for now but I will get use to it soon.

What do you think