Not OP, but I started my shed (I think) 8 years ago.
Year 1: dig, place and level footings. Put down floor joists: it's just a little 8x10 shed, so they're 2x4's
Year 2: find some scrap 3/4" plywood left over from another project for a floor. Realize that it'll just get wet and rot if placed, so leave it where it is. Instead frame and raise the walls.
Year 3: realize that you should have built the south wall a bit higher so the roof can slope, shrug and figure out a way to frame the roof so there's a small slope anyway.
Year 4: (I think). Find leftover metal siding and nail it in place for a roof. Now that we have a roof, put the plywood down, but don't nail it down since without walls, it could still get wet and rot.
Year 4.5: realize that the proto-shed is usable as is, and start throwing crap in there that needs to be out of the way, but can take getting wet.
Years 5 - present. Look at the shed and realize that with less than a day's work you could finish it but don't have the motivation to go find more siding, drive over there, drive back and then nail it up. Maybe next summer...
Summary: The guy bought a house and decided he wanted to build a shed. He bought the plans, poured the slab, and then life happened.
Basically, every time he had time / money to work on his shed, some kind of obligation came up or some kind of emergency ate away at his shed funds.
IMO, I think it's just a case of the shed not being that important, but the joke being "worth it." If it really was important he'd have figured out how to finish it more quickly. (It's not that expensive to have someone deliver a small shed to a home.)
Year 1: dig, place and level footings. Put down floor joists: it's just a little 8x10 shed, so they're 2x4's
Year 2: find some scrap 3/4" plywood left over from another project for a floor. Realize that it'll just get wet and rot if placed, so leave it where it is. Instead frame and raise the walls.
Year 3: realize that you should have built the south wall a bit higher so the roof can slope, shrug and figure out a way to frame the roof so there's a small slope anyway.
Year 4: (I think). Find leftover metal siding and nail it in place for a roof. Now that we have a roof, put the plywood down, but don't nail it down since without walls, it could still get wet and rot.
Year 4.5: realize that the proto-shed is usable as is, and start throwing crap in there that needs to be out of the way, but can take getting wet.
Years 5 - present. Look at the shed and realize that with less than a day's work you could finish it but don't have the motivation to go find more siding, drive over there, drive back and then nail it up. Maybe next summer...