Agreed. sizeof FEELS like a function, and so I use parentheses with it, even though I know it's not actually a function.

Wasn't there some subtle difference between using sizeof with vs without parens? Something like if you pass a type to sizeof -- e.g. sizeof(*int) -- you must use parents anyway? It's been years since I've used C, I'm probably not remembering it correctly.

Yes, exactly that. `sizeof(int)` OK, `sizeof(i)` OK, `sizeof i` OK, `sizeof int` not OK. One of those weird rules.

Why is sizeof a terrible keyword? Just think of it as an operator rather than a function.

Should have been a callable, or should have had consistent syntax to prevent people from being clever.