Repair kits were not in the original, traditional 10 Essentials lists, although they obviously should be. But this is one "essential" that has to be tailored very carefully to the kind of outing.

I lead snowshoe trips for various organizations several times a winter and end up repairing broken snowshoes on every single trip, including short, easy half day hikes. Since I have gotten to know which parts break most often, I carry a bag of spare parts.

On occasion, I lead ski tours. While these are short, easy tours intended for nature study, still, there is the occasional ski or pole breakage. Again, like snowshoes, certain parts break more frequently, so a variety of spare parts is handy. Baling wire (yes, baling wire!), an assortment of screws (with real screwdrivers - multitools are inadequate for this), hot-glue sticks, and wooden golf tees are essential repair items (when a screw pulls out, hot-gluing a golf tee allows replacing the binding with a screw). I have only had to use a spare ski tip once, but it was far enough that it would have been miserable without. Splints are necessary if anyone in the group has fiberglass or carbon fiber poles (I have had people show up with bamboo poles, too!).

Summer hikes are easier to deal with, but gear still needs repair. Hot-glue sticks work wonders with the boot sole that came off (a Bic lighter works just fine for melting the glue). I have used the pliers on a Swiss Army Knife (the Deluxe Tinker) to do orthodontery (twice kids have broken wires on braces and it was necessary to remove the sharp wire).

Dental floss is probably the most used repair item I carry. I collect the give-away sample teflon-coated floss sample packs every time I go to the dentist. I can't remember all the items of clothing, tents, and sleeping bags I have repaired with dental floss, not only for myself, but other people on the trips.

The lead-in suggests "consider" a stove maintenance kit. I would put it a lot stronger than that - if you carry a stove, ALWAYS carry the maintenance and repair kit made for your stove. Even if you do as you should (perform maintenance after every trip and inspection before every trip), sooner or later you will need to do a repair, especially if you take a lot of extended trips.

I carry glue sticks to fix waders, fishing rod guides, or whatever, It's good to know I'm not a freak. Ha!
My MSR whisperlite came with a repair kit, so far I have only had to lubricate the pump cup once and replace an "o" ring that I lost. Good thing I had a spare!

It's foolish to venture out on a mt.bike trip without the means to make necessary repairs on the trail, but people do it every day. Tire patch kits are great, but sometimes you need more, like a spare tube or some TOOLS. With the advent of specialized bike multi-tools there's almost no excuse for not having the tools you need - even if YOU don't know how to use them.

Back in the late 80's, when I guided trail rides in the Poconos, I patched countless inner tubes for people who didn't know how. Once I came across a guy who had pushed his bike for quite a few miles because of a broken chain. He didn't know how to fix it. I offered to help and, in an instant, he dumped the shiny, still-in-their-original- packages, contents of his way-too-new backpack that he had allowed the bike salesman to sell him, on the ground in front of me. "That's what you need, right there!" I said. "A chain breaker". "But it's already broken." he says to me. I ignored the comment. It took all of 5 minutes for me to show the man how to replace the broken link and then, he was on his way. I guess that salesman "had a feeling" about this guy. Or, maybe he knew he'd meet me :)

I guess the moral of the story is (as it always is from me) If you take it, know how to fix it. And if you have the tools to fix it, know how to use them too.

f klock you are so right! Lots of people are familiar with the phrase "Be Prepared" and apparently think it's just a cute saying.
I certainly don't claim to be the best at anything, but I learned what to take and how to use it. I've always considered that common sense.
Too many people just head out and assume that everything will be ok.
In all fairness I know that people are just eager to get out and have fun, and we all have to learn. You shouldn't have to ask if you can "borrow a band aid" for petes sake!