1. No, I don't have a special interest; I have several. Unfortunately I ended up being the kind of guy who gets definitely into a bunch of things: some of my longest-lasting interests have been antique hand cranked phonographs and gramophones, but I also like horses, cats, nature, wildflowers (not yet at full infodump level on botany tho), birds, birdwatching, history, machinery, typewriter restoration, antique clocks.
2.
Infodump that could be handy? Some stuff I have found out messing around in my various hobbies. Most of my special interests could be appropriate for boring old normal life at the turn of the century but here is a pile of random stuff I've picked up.
--never use solvents in a kerosene lamp; the flash point is too low. Use only clear pure kerosene or lamp oil.
--if a shotgun has Damascus Twist or laminated steel barrels, do not load it with smokeless powder--they tend to splinter right at the fore-grip. Black powder is the only safe munition. It does burn hot, though, so if you are shooting a double-barreled gun (thin walled barrels & tiny grips) you may wish to wear gloves.
--Singer sewing-machines function OK on plastic bobbins as well as metal ones, if it's the Class 66 bobbin.
--if you're riding a horse & he won't go forwards when asked, don't kick him; ask him for a tight turn to either left or right and when he yields by moving his neck, now -- leg pressure on the inside -- he will disengage at the hind end and make a tight turn. Once he does, ask for him to walk straight on. Repeat if he keeps balking. Now you've tricked him out of balking without making a fool of yourself.
--You can leave the living room Victrola wound up a little bit and it won't hurt it, but if you want to leave it parked for a long time, switch on the motor & allow it to run all the way down.
--Do not wear a mechanical watch near a strong magnetic field.
--To start an older automobile: follow the startup procedure in the manual, but for heaven's sake do not wrap your thumb around the crank handle or you will be sorry if the thing back-fires and tears your hand up.
--Traditional "roadster" bicycles have the same brake arrangement as a motor-cycle. The left hand operates the rear brake, which is the opposite of the American arrangement. But it doesn't matter. Those brakes never worked that well to begin with!
--When type-writing: keep your wrists well off the keyboard and sit straight up, looking at the paper instead of the letters on the keyboard. With practice you will be able to go much faster this way.
--If you wind your watch at the same time every day, it will be more accurate.
--Iron gall ink is indelible, but do not use it in a fountain-pen with a steel nib. It invites corrosion. Use it in a pen with a 14k gold nib instead, or, in your steel pens, use a more conventional writing fluid like Sheaffer's Skrip or Diamine.
--You can sharpen a razor-blade in a glass of water if you wore it out & need to shave.
--To make gramophone records last indefinitely, play them with a bamboo or fiber needle. Check the soundbox on your gramophone: if the needle socket is triangular you can use that. If not? Use a thorn. The thorns of the locust tree, carefully dried, are nearly as good as steel needles.
--Putting a new wick in a lamp: char the wick by lighting just the end of it and letting it burn out, before you ever put kerosene on that wick. Once you have a good charred surface you can put your lamp together & fill it up with oil. Let it stand at least an hour before lighting, preferably longer.
--Every couple years take the telephone apart and, with the tip of a needle, place a drop of oil on the pivots for the dial. It will prevent the dial from giving wrong numbers.
--3-in-One Oil is not good for a clock. Use clock oil. WD-40 cannot be used for cleaning clocks either.
--WD-40 can be used to clean shellac gramophone records. Denatured alcohol cannot.
--You can use Vaseline to fix a creaking door. Rub it on the hinge pins. This is less messy than oiling them as the Vaseline cannot run down the paint or spoil the wall-paper.
--To get more eggs from chickens--make sure there are no snakes in the area; they may take up residence in the chicken house and eat the eggs. You might not see them either. I found a large one hiding under the straw in a chicken nest, where he had been for weeks.
--Opossums will not bite you and are harmless.
--The green snake has two subspecies: rough and smooth. Rough green snakes have keeled scales--the scale has a ridge like the bottom of a rowboat.
--Do not paint a house in the middle of winter. The paint will not stick well & you will be repainting it anyway.
--When you are done playing the organ push all the stops back in. This keeps the mutes from sticking. Only pull out the stops you intend to play, when you intend to play them.