I don't think you are ever really "done" with load development. Your load is only good for as long as you have the components you used to develop it, and as long as your gun will shoot it without wear affecting it. I do think that after you do get a good load developed, it's a bit easier to keep it shooting than it may have been to find it. Especially if you did what you were supposed to do and record everything about the load and how you got there.
I keep a running journal, save targets with data, etc to help out with that.
If I didn't enjoy and get so much satisfaction out of the entire process of load development, hand loading, shooting, and tinkering with guns, I'd have stuck to factory rifles and ammunition.
I've always been this way with everything I do.
I have to enjoy being totally immersed in all facets of whatever it is, or I find myself not doing it.
When I find myself getting tired of it, or making it work instead of fun, that's when I know it's time to take a break, and enjoy something else I like to do.
Everything is always right there, waiting for me to pick up where I left off.