I had the same thing happen to me lately, but I was at the stupid end. I am not a programmer by profession, so it matters very little to me, but I had been struggling to produce a correct solution to a seemingly simple problem (writing a macro to allow definitions in expression context in r6rs scheme). My solution worked but had the side-effect rewriting obviously bad syntax into correct one and not in a good way.

I was struggling with how to do it correctly, and then one of the people in the r7rs working group simplified the problem by a very large factor by pointing out to me that I was trying to solve a non-existant problem, because I tried to add definitions to expression contexts where it simply made no sense. In fact, instead of supporting all forms, I could get a better result by just focusing on one of them and add simple wrappers for another 5.

It was all quite humbling. Had I taken a step back and actually analyzed the problem I would have come to the same solution, but I immediately tried the, to me, most obvious and also hard-to-get-right solution.