What's on your list?
"I have kids at home, I don't have a manager, I need to pay off student debt, my boss never lets me, I'm really busy because of soccer season, my knee is acting up, there's already five galas coming up, my RSI hurts when I type, I don't have a degree, I have a degree and can't waste it, I'm not good at that, I tried it before but it didn't work, I've never tried it before, the weather is crazy, isn't it, the election is right around the corner, it's been too long at this job they won't listen to me, I'm going to retire soon, I'm too young, I'll never learn, it's too risky..."
We all have a list. Most of the things on it may in fact be legitimate reasons for no.
I guess the self-marketing question is, "how often do you remind yourself of what's on the list?"
If the first thing you do when considering an opportunity is consult the list, the list is the most important thing in your life, isn't it?