Although I'm a Mac user for several years now, this noob-question is stuck in my head since the beginning:
I'm selecting a text by holding down Shift and moving around with the cursors.
Imagine I start at one line, press Down and then want to move my selection end to the beginning of the line (just like pressing Left all the way): how do I do that on Mac?
Pressing Home or Cmd+Left always moves the beginning of the selection to the beginning of its line (which is also kinda cool, but doesn't help me here).
I've even made a gif about this to demonstrate: