Most "mature" readers surely have heard the old saw about newlyweds, the first year of marriage, and a jar of nickels. I'll spare you the details, but basically the jar never empties. A motorcycle restoration is similar, in that the first step involves putting parts into containers, and the last step involves taking them back out. And unless the bike was so nice that it really didn't need to be restored in the first place, the containers never get completely emptied. But the enjoyment timeline is inverted for restorations; the most fun is in emptying the containers, not filling them.
And it's not just jars, although jars can be used for fasteners and other small bits. When a crusty old bike comes apart in Fred's garage, the bits go into Ziploc freezer bags, Rubbermaid plastic tubs, coffee cans and old Christmas cookie tins (sorry Santa!). I try to avoid cardboard boxes and milk crates. Oozing chemicals break down the adhesives holding corrugated boxes together and little bits fall through the holes in the bottoms of milk crates. A milk crate can inadvertently be a "sifter" for parts: each time it's moved a few more special nuts or bolts or other small parts escape to the floor and join their fastener buddies, mouse turds, and mole crickets under the workbench.
Freezer bags with the little white panels are great for labeling with a Sharpie, at least until the label has been crossed out and renamed a few times. By that time the bag usually has a nice interior coating of rusty grease or brake fluid, making it hard to ID the contents visually. It's a toxic treasure hunt! Depending on how long a restoration takes, reopening containers of parts can be a trip down memory lane, if memory lane is the road to a particularly noxious Superfund site. Gear lube, penetrating oil, coagulating brake fluid and ancient ($1.25/gallon!) gasoline, sealed up together for a few years, combine for some trippy smells.
Some folks exhibit poor decision-making when choosing parts containers. Twenty years ago I answered a Bargain Mart ad (pre-eBay when the Bargain Mart had a better selection of motorcycle and parts ads) for a Honda CB400f, "needs work." The would-be seller had disemboweled the poor little 400-four and stored most of the major organs in the trunk of a dead Impala (a yucky '80s Impala). Upon inspection it became obvious that this rolling container was the repository for several other dismembered bikes. It's a safe bet that those parts were in that Impala when the whole package was shredded to feed China's appetite for scrap steel.
Many of the hulks rolled into Morristown's Motorcycle Salvage come with containers of parts, left over from aborted restorations or owner servicing. I've seen buckets, clutch covers, and other odd receptacles. When the guy put his Ninja's transmission in an ice-cube-maker bin, he wasn't planning on their staying there for eternity. So far he's wrong.
Tearing down a bike is often a messy, stinky business. Usually it's at the disassembly step when I determine which bits are salvageable and which are scrap, but of course that doesn't mean I throw them away! The reject pile ends up in its own container, to be labeled and stashed in the crawlspace, eventually becoming its own little Superfund site.
Along with rusty hardware and used gaskets, rubber parts are often likely to fail the usability test and end up being replaced. Either by disintegrating entirely or fossilizing to Bakelite, early elastomers just can't hang with 30 years of UV and ozone. They soak up old brake fluid in the bottom of the tub, getting unnaturally swollen and jellified. Even a pack rat like me can't justify keeping that crap.
But with decent labeling and some close-up digital photographs, even a newb can get all the parts back where they belong, despite the misleading perspective the Italians and Japanese seem to have in the exploded diagrams in their parts manuals.
As containers are emptied, you feel like you're actually making progress. Components get cleaned, painted, polished, or otherwise refinished, and retake their places on the gradually rising pile, eventually recognizable as a motorcycle again. Wiring harnesses that haven't gone stiff from internal corrosion or been butchered with those horrid splice connectors get wiped down with WD40 and zip-tied back in place, a little dielectric grease easing their bullet connectors back together with a satisfying click. Soon it's new battery day, and if I'm lucky, electrons squeeze through the old copper to illuminate instrument bulbs dark for decades. If I'm less lucky, the smoke that's been in the wires since the bike rolled off the assembly line escapes, sending me to eBay looking for a good used harness.
Later milestones are installing the refinished sheet metal and the first attempt at starting, after first spinning the motor with the starter, plugs removed, to build a little oil pressure. Shake-down rides, final tuning and adjustments come next. But the last step is boxing up the leftovers, wiping the rust and goop out of the empty containers, and putting them away until the next project. Try that with a jar of nickels. (You Viagra/Cialis/Levitra guys, please spare us the letters telling us how empty your jars are.)