IMHO Write it once for the problem; again for the solution.
TFA stresses: finding out what you're building; finding the "unknown unknowns" (the things you don't even know you don't know, encountering those problems)
TFA doesn't say it this way, but I think the fun of throwaway-prototyping is your thoughts can focus uninterrupted on the problem, undistracted by secondary issues. You can hack-around tedious parts, now knowing they are there; and you can get absorbed in the genuinely tricky parts, unobscured (even if you don't succeed, you also know they are there). You're not expected to get it all right.
It's turning an unexperienced developer (on this problem) into an experienced one.
"you should plan to throw one away. You will anyway."
That was the first edition of The Mythical Man-Month. In the second edition, I say that was misguided! You ought to plan to continually iterate on it, not just build it, throw it away and start over. Some of the things I said in 1975 were wrong, and in the second edition, I correct them.
TFA stresses: finding out what you're building; finding the "unknown unknowns" (the things you don't even know you don't know, encountering those problems)
TFA doesn't say it this way, but I think the fun of throwaway-prototyping is your thoughts can focus uninterrupted on the problem, undistracted by secondary issues. You can hack-around tedious parts, now knowing they are there; and you can get absorbed in the genuinely tricky parts, unobscured (even if you don't succeed, you also know they are there). You're not expected to get it all right.
It's turning an unexperienced developer (on this problem) into an experienced one.
PS Somewhat disturbingly, Brooks went back on this according to this interview https://www.computerworld.com/article/2550685/the-grill--fre...