Why is “north” “up” on a map?

I don’t understand the question…

By Tobias Jung [CC BY-SA 4.0], via map-projections.net

By Tobias Jung [CC BY-SA 4.0], via map-projections.net

By Strebe – Own work, CC BY-SA 3.0, Link

Ok… it’s because the map makers (cartographers) that made the first maps drew them from “their perspective” and now, as you might have figured out from the above projections, it gets a bit hard to compare if it doesn’t continue somewhere along the same line…

Header image: By Strebe – Own work, CC BY-SA 3.0, Link