Exploring the backcountry or back roads with your bike is a blast. Packing some extra kit to spend the night makes it even better.
Each night before bed all good trail builders bow their heads and mumble something along the lines of "I will build sustainable trails". Come morning this translates to designing and constructing fabulous singletrack that will require only minimal maintenance regardless of rainfall and volume of riders.
The lingering memory of the last summer ride on your favourite stretch of singletrack is often enough to get you through the winter chills. Sadly a quick mid-winter reccy of that favourite track reveals a wet, unrideable mud-fest.
Feel the envy of all those frustrated drivers as you scythe through traffic jams en route to work. Cycling around town is hugely practical - it's often quicker than a car and there's no risk of being wheel clamped while enjoying a brewski or a movie.
The back of beyond is a long way from workshop tools and spare parts. So when big crap happens, you'll need to make like de Bono and dredge up some lateral thinking to limp home.
It's a bummer but your mountain bike needs care, love and attention (just like the family cat).
You need to carry enough tools and bits so you can hobble home on your wounded bike but not be laden down like a US Marine.