What does'Notice me Senpai' mean?

It honestly bothers me when weebs use 'senpai' to denote their significant other. Senpai means upperclassman, or a higher-level student.

Its a meme/joke that originated from japanese animated shows (anime), basically a common theme in the high school anime genre is that a junior student has a crush on an upperclassman (senpai) and is always trying to get their attention. Soooo it kind of morphed into a 'joke' (which can honestly get annoying lol) and people just say it anytime they want someone's attention.

I don't know what anime it originated from but now it became a meme/joke honestly it's a bit annoying