+1 The worst code I had to maintain was code that tried to follow DRY (without the trying to understand what the original intention of that principle was). The only way out of that mess was widespread code duplication.
It'll be fine, don't worry about it: just add a couple more obscure boolean parameters to that reusable function to support your new use case and ship it.
Yep. Keyword "tried," as in they did it for a while then hit a point where it's impossible to faithfully follow the abstractions because they're wrong.