VIM textwidth has no effect

Question

This feels like a dumb question, but I can\'t find an answer on the Internet (or in VIM help). I\'m using VIM 7.2 on Mac OS X. All I want to do is wrap my lines at 72 characters

Answer 1

What does

:set formatexpr?
:set indentexpr?
:set cindent?
:set filetype?
:set paste?
:filetype

print.

At least one of those (and I think all of them) will override the setting for textwidth.

For example, if you're editing a C source file, the C indent rules override textwidth.