I'm changing out the lenses on my camera and I look down and realize I've gotten an amazing amount of dirt and dead leaves in the interior of my little kit lens. I blow into it, thinking I can just dispense with the mess, but when I look down again, there's even more debris inside the lens. I tug on some kind of string, thinking it will pull the bad stuff out, and the entire guts of the lens come tumbling out into a pile.
There are people around — presumably people who know how to deal with camera equipment — and as soon as I show the lens (what's left of it) to a white-haired older gentleman, he shakes his head as if to say Too bad, that lens is FUBAR.
I set about trying to reassemble the lens shortly before realizing I have no idea how a lens' interior should even look.
I feel like a total fuckup but I'm not too disappointed because I've been wanting to get a new primary lens for a while. And yes, I did think of that exact lens in the dream.