Planning, researching, and documenting, however... These things, I would wager, do not hold the same appeal for most.
I love putting numbers to things, though. I love the attempt to quantify. I love using calipers and scales; writing things down; building folder structures; storing away pdfs, models, drawings, and notes. I love creating confidence that bits and pieces will fit together as intended not just on part #001, but on #002 through #999 as well.
99.9% of my job involves bicycles in no way at all. I'm a mechanical engineer contractor/consultant, and I work in any industry that wants me. There's not a lot of intrinsic excitement in, say, weatherproof housings for power transmission equipment, or fast food menu display monitors. The numbers make it all interesting, though. The numbers make it worth doing. On the rare occasion I get to mix the tools of my trade - CAD software, calculator tricks, E2 paper, math love - and bikes, it really seems like things can get no better.