I love the quote. The Doctor is badass. But ultimately this seems to be a quote about misusing the word 'impossible' - totally out of place in this thread!
I see it as taking the Outside View on impossibility. Of course, in real life it usually takes more than a few minutes, but in the Whoniverse it is not unreasonable. Also, asking "How impossible?" seems to me like a good question in some cases.
Here's the new thread for posting quotes, with the usual rules: