Sometimes you say you can't do something because you really can't. Other times, you're just making excuses. A good way to tell which one it is is to use the million dollar scenario.
When we have a student who repeatedly misses or arrives late to meetings but always seems to have an excuse (traffic, too busy, I forgot, etc.), I'll ask,
"What would you do if you knew you'd win a million dollars if you arrived at your next meeting on time?"
I'm not looking for, "I'd be there on time." That's too easy. I mean what specific actions would you take that you're not taking now?
The student inevitably says something like , "I'd write it down so I wouldn't forget" or "I'd leave earlier to beat traffic." The million dollar scenario exposes when you're making excuses for things that you really could do if you wanted to.
I'm an equal opportunity user of the scenario; I'll use it to call myself out when I'm just making excuses, too. People in my life would tell you that I often think I'm busier than I really am. When I think I'm too busy to get a project done on time, I'll use the million dollar scenario, and it calls me on it. Every time. I used it 11 months ago when I thought I was too busy to write a post on this blog every day. I haven't missed a day since.
I'm not saying you should necessarily always do what the million dollar scenario suggests. If there were a million dollars riding on you getting a 4.0 this semester, but in order to do it, you'd have quit the jazz band you love and sleep 3-hours a night (probably not true, by the way), that's not improving your life.
The million dollar scenario shouldn't push you to do things that will make you unhappy; it should push you to get out of your own way and achieve the goals that will make you happy. It should help you prioritize your responsibilities and make better use of your time.
When it's important, knowing there's a million dollars on the line can really make you focus. Give it a try and see what happens.