I’ve been there. You’ve been there.
When your wondering why your player movement isn’t working (or is choppy), check everything under the sun… only to realize you forgot to put move_and_slide() in _physics_process and it solves every issue.
This isn’t even a complaint or suggestion, just an observation I had.
never forget about it 
but i understand your frustration 
You know, I really though more people would relate to this.
I guess not.
Edit: And it seems no other Godot developer has ever made this mistake, except me apparently.
I made this same post on the Godot Reddit (bad idea) and I got not even a wink of solidarity. Only snark and anxiety. (I deleted my account after that because I fell into a depressive slump) (I really hate Reddit)
but what most people forget is the semicolon" ; " its not so for python, lua and GDScript users, but people that use other languages will always forget it.
hey! but today i forget to put move_and_slide() !