It's probably a myth that professional Roblox scripters know everything to script. Which could be true, but also very false. I'm a learning scripter that gets a lot of errors and confusion while scripting. How do you professional scripters know how to script so well? I've watched the entire Peasfactory tutorial (I can't remember every single thing in that). I've learned a lot of that, but for example: I don't know how to make keybinds and the roblox developer page explained that poorly. How do you know that? And what are some over-advanced ways of learning Lua?
I will suggest having a notebook and writing everything down. This makes you remember what you've learnt also if you want to know how to script anything off by heart. YOU MUST first learn the basics. 1.Memorilise everything you've learnt try to test your self. And 2. Follow all youtubers and try to copy them at the same time so for instance. If they're making a script. Copy it down and try to understand it. It takes practise.
The best way to learn scripting is by the following: YouTube - watch beginners series to advanced series Roblox Developer hub 100% Roblox Studio - trial and error
i'm not a that advance of a scripter still a noobie but I think a good way to learn is asking a lot of questions like why something works or why there is a error in the script if your stuck on it because someone would tell you and help you understand it