I have the habit of immediately closing parentheses after opening them, then insert the code.

The problem is, this applies to hand writing as well. Because you cannot move characters in a hand written exam I spend half of the time writing, then removing parentheses.
Whyyy brain

And I don't have that habit, so every time some text editor tries to be smart I switch back to Vim.

Now and then I forget to close a bracket, but these errors aren't hard to find.

Same here but for code only. No bracket errors even when coding, even when I'm forced to code in nano.

PS. Anyone who tell students to write code on paper on the exam is retarded. Middle Ages ended long time ago

I do this in Excel, but when I hit left arrow to go back and fill in the formula, it thinks I'm trying to input the cell next door. It's very frustrating.

@lb13 click F2 and then you can use arrows :)

Yes yes yes... And it's not only the braces... I write all function titles first, then a sorta algorithmic skeleton, and then the actual code. N i keep gng up and down and left-to right and right-to-left. Ppl who see me say i code frm all directions😶 And so in exams, i feel crippled😞