It's relative to the boat, so that if you are standing on deck and looking back everyone knows what you mean and not if you are talking about your reative left or the boats.
Port was also initially Larboard, but it turns out when shouting a direction from the other side of a boat, having two similar sounding terms for opposite directions often results in crashing said boat, so it was changed in the mid 1800s.
Except we say drivers/passengers side when referring to the side of a car. People dislike port because they can't remember it from lack of use. Insecurities cause this whole discussion.
I don't use it often at all, but when I was 6, I just remembered left/port had 4 letters and haven't forgotten yet. Some day I might, but me forgetting doesn't mean I should ask everyone else to stop using language.
E.g.
I have a plethora of grapes.
We should stop using the term plethora because they could just say "a lot."
E.g. I have a plethora of grapes. We should stop using the term plethora because they could just say “a lot.”
That reminds me of the old joke:
A widow was holding a funeral for her husband, when a man asked if he could say a word. "Of course" said the widow, so he stood up and exclaimed "plethora!". The widow replied "thanks, that means a lot".
Also if you always say "left and right" instead of "right and left" (which must english speakers probably do) you can remember that port and starboard are the same order.