How many times have you thought that in the course of your day?
I'm not ready quite yet to tackle that problem; I need to research, talk to some people, have a meeting. After I think it over a little I will surely come back with an idea.
I'm not ready to start writing that book that is in me. You all know there is at least one book in each of us, right?
I'm not ready to go home and enjoy a good day, I have to finish this project first. It will be just a minute, I'll call when I get on my way.
I'm not ready to meet him/her yet. I need to learn more about the subject or (alternatively) I need to lose weight, become taller, be more athletic, learn another language. Insert your favorite requisite there.
I'm not ready to blog, what if I do not have any more ideas? What happens if nobody comes to read my posts? What happens if too many people read my posts and they don't like them?
Most of the people writing books which insist on "being exceptional" won't admit this publicly, but it's true: merely being "good enough" will probably not lead to great in the long term - but good enough is often better than not at all.
It's an inch closer in your self esteem, learning, growth, experimentation, passion, and confidence. You are always good enough and ready.