It will be under the left rear foot of the beer fridge in the garage. - That is where most of my dropped bolts end up. Or in my sons bedroom - he has a habit of collecting 'spare parts' as he calls them, from my work bench. I suspect he is quietly collecting enough parts to build himself a mini-bike!
Go to your local Honda dealer and ask if they have a "Junk drawer". I don't know if it's a good thing but my local Honda shop has one full of misc. bolts and screws
That will be from rebuilds on customers bikes - there is always at least one bolt left over .........
A friend rebuilt a XL Honda motor years ago and had a jar of around 6 really important looking bolts left over before we fired it up - he started it anyway and that engine ran like a dream for years!
Plus I think the bike & car shops nick them ...... most times I've paid for a service I usually find a bolt missing - air cleaner cover bolt, side cover etc etc. I had a auto serviced on a car and they had forgotten to tighten up an entire engine mount that had to be dropped during the service! I wondered why it was shifting poorly on the way home so stuck my head under and had a look!