I've been very lucky with managers. I've had three different managers in the last 15 years and all of them have been great. One former manager, who no longer works at this company, is now my best friend and we're going to a concert next month.
Well, I had to call my manager earlier and let her know I was gonna miss a deadline because I just didn't want to work on this project (writing instructions for Windows XP users). I have made everything else a priority—including writing this posting. BTW, this isn't my modus operandi. I'm reliable and I get things done whether I have to come in on a weekend, stay late, whatever. But, not this project.
Anyway, she was so cool. She said "I get it and I'm doing the same thing—postponing work that needs to be done."
So, I'm thankful for flexible managers who "get it."