Until you do something else for a few months and come back to realize that instead of there being only a single person in the world who understands your homebaked framework, now there are none at all.

I speak from experience.

I'm literally living the experience right now.

> but if you have written the framework, you don't need to go anywhere for help.

Sure, if you're a genius who knows how to solve every problem, can keep the entire codebase in your head, and remember every change you - or someone else on your team - has made.

I'm doing some contract work for an old employer that uses a home-built framework that I've worked on and improved extensively. I'm betting it'll take me another hour to truly catch up on the ol' codebase enough to actually write something useful. And if I have a question about something? Well, I hope my old coworker has been keeping up with things enough to remember the answers that I've forgotten.

"but if you have written the framework, you don't need to go anywhere for help." Never had to come back to an old project or a part of an active project you haven't touched in ~6 months? I spend a fair amount of time figuring out why the hell I did X or Y a year ago, even with source code docs, narrative docs and tests. I don't think I'm the only one.

edit: what Vivtek says :-)