Some great posts here.
I've had some ups and downs in the hobby.
I've had months where I just played the crap out of pins, that just one more game feeling.
Other times I haven't gone near them for ages.
I'm going through a bad time ATM with some bad medical issues and have lost the feel of playing.
My partner who is also a pinhead try's to get me playing again but ATM I'm not feeling it, as she throws her high scores on my pins lol.
There's no time limit on when your mojo will return, and it will return. Always concentrate on heath matters first - the machines will be waiting for you when you are good and ready.
Generally speaking, I've seem many friends grow tired of their collection or love of the machines. People change over time, and there are a host of reasons why they do what they do. What has happened in every singe case - all of them - the mojo eventually returns. I've seen LARGE collections moved on for peanuts... Then years later, the thrill of the chase returns. The Addams Family sold for $6K 10 years ago is now available again for the bargain price of $16K..Dammit. My situation is privileged - I'm around them all day, every day. "Pinball" NEVER changes for me, they are literally "in my blood" - But "people" change constantly.
Collection wise - As long as there's room, and the thrill of the chase is still there, the hobby will always be fun. Maybe when the games room is full, satisfaction of filling it may be enough. Maybe there is some disappointment, as there is no more chasing. I don't actively chase games anymore, I wait for them to find me. But whenever I find one, the excitement returns.
One thing that hit me in the face was losing two great friends - Greg and Gavin. They both worked hard and had incredible collections. They cannot enjoy the games any longer, and it disappoints me greatly. They were both heavily invested (money and time) in their collections. Enjoy yours while you can. That's what they are there for.