Wiggy what part of are you ready aren't you clear about?
Let me think.... Yep, got it thanks, I'm so glad I got this far in my aviation life without realising what that call meant - thanks for pointing out the gap in my knowledge.
You're perfect of course, but some of us have encountered situations when you were ready, called it, been lined up and then for unknown reasons you're suddenly not ready (cabin, EICAS, etc)...and if any critical thinking is involved ( along the lines of is it even safe to taxi?)perhaps you just need ATC to stand by for a few seconds.
I don't know what went on on this flight, I suspect neither do you...