I too, have been gone too long - and there are a lot of reasons contributing (none of them great or substantial, mind you). I've decided to go back to school at age 43 to finish my degree (about 2 years left if I go non-stop year round), and have also changed to a different role within my company.
Nonetheless, my current stash of products hasn't passed the 2 year mark, but it's getting close. I don't want to throw away bottles that have 80% of their content in them, so I'm hoping that I can still get some use out of them - even if it's at reduced effectiveness that might require more passes on my part.
I bought a 2013 Harley-Davidson CVO Road King last fall that has some of the softest paint I've ever encountered, and there are now several spots on the front fender and hard bags that need paint correction for the light scratches that are there. I had no problem doing paint correction on my cars (with the PC), but I'm extremely nervous about trying to do it on my new motorcycle (most expensive vehicle I've purchased to date). If the paint is as soft as I think it could be, I'm worried that I will take too much off in the paint correction process.