Is changing your password at work every six months a waste of time?

I hereby challenge the conventional wisdom that changing your password often makes your computer more secure.

Seems to me that not changing your password every six months is less of a security problem than my neighbors who can’t remember their passwords and therefore write it down on a post in note that goes right on the monitor and every six months, those office neighbors of mine take down the post-it password and put up a new one, totally wiping out any security benefit gained by changing their password in the first place.