When faced with this choice, a powerful truth emerges: you need to have a vision for yourself! Surprise, surprise: that takes work, too. Often, we let shoulds replace doing the work of figuring out what our vision is. Remember, you will work hard regardless, but developing one’s vision seems to be the work that some of us would rather not do. It is far easier to let shoulds lead the way and then judge those who don’t bow to shoulds as selfish and self-centered.
What does this refusal to should all over myself look like in practical terms? Above all, it manifests as a commitment to drawing boundaries and saying “no.” Is this easy? Of course not, especially not in academia, where everything is structured around favors and unpaid labor. The difficulty does not make it any less crucial, however.
Saying “no” is like exercise: no one can do it for you.
When do you say “no”? The answer must come from your vision for yourself and the contribution you want to make and from knowing your limits. If a task does not fit into your vision or it is beyond your capacity, then saying “no” is the sane and healthy response. Period..."
~ Koritha Mitchell, "Should-ing All Over Ourselves," (Day 5: The Feminist Wire's forum on Black (Academic) Women's Health)
http://thefeministwire.com/2012/11/should-ing-all-over-ourselves/