Does it bug you when people say "of" instead of "have"?

For example, "I must OF done that earlier" instead of "I must HAVE done that earlier." Is it just me, or does the first one not make sense? "You should OF come over" is WRONG!!! yeah, when you say it, it sounds like "You should've come over" which is correct, but when people type it out, they write "of"!! NOOOO!! Does this bother anyone besides me??