When I first started programming, I wrote an app where I had a bunch of similar functionality which I wrapped up in a neat little 20-30 line function ... I was very proud of myself for writing such an elegant piece of code.
Shortly after, the client changed the process in very specific cases, then again, then again, then again , and again, and again .... (many many more times) My elegant code turned into a very difficult, hackish, buggy, & high maintenance mess.
A year later, when I was asked to do something very similar, I deliberately decided to ignore DRY. I put together the basic process, and generated all duplicate code. The duplicate code was documented and I saved the template used to generate the code. When the client asked for specific conditional change (like, if x == y^z + b then 1+2 == 3.42) it was a piece of cake. It was unbelievably easy to maintain & change.
In retrospect, I probably could have solved many of these problems with function pointers and predicates, but using the knowledge I had at the time, I still believe in this specific case, this was the best decision.
