Wishful thinking is mentioned several times in SICP, both in terms of to be implemented functions and in separation of concerns.

Oftentimes in the book, they will write out a function with reliance on a variety of other functions that haven't been written yet, but which show a blissfully declarative outline of exactly what the function does. Then you go and write the sub-functions.

Looking at the code after is quite nice, but it takes a bit to wrap your head around writing large swaths of code that can't run -- especially when you're used to writing REPL-driven code and consistently checking/"testing" it