"How do I do it? I don't know how I wouldn't do it - that's the thing"

In this quote, fashion designer Isaac Mizrahi is expressing his uncertainty and confusion about a certain job or situation. He is questioning how to approach it and admits that he does not have a clear answer. Nevertheless, he likewise acknowledges that not doing it is not a choice for him. This might recommend that he is figured out to discover a solution and is willing to put in the effort to make it take place. Using the word "thing" at the end of the quote includes a sense of vagueness, highlighting the complexity of the circumstance and the trouble in finding a solution.