I think our default answer is too often (as in almost always) 'no.' Or, waaaay more accurately, at least in my case, 'I don't want to.'
Now, there's a fine line here--some things, some offers, some opportunities, some options just don't resonate with the song your soul is playing, and I hear you. Say 'no' all you want, up and down the scale.
But some offerings nudge gently at that familiar melody--and you can always tell, down in your heart of hearts, that this particular addition, were you to embrace it, would add depth and feeling to the music you've been playing all of you life. And yes, that's scary. And yes that takes adjustment and a bit of tuning. But isn't it worth it? Isn't this the music you love? And isn't the practice, really, if we're honest, one of the most beautiful aspects of living?
So--just for today, why not?