What other hobby...


has has an infinite number of variables like this one?
needlebrush
Not a downer if you get it... but, preparing to die. (Hopefully not for a long time!) The older I get, the more my perspective on all the activities and fuss evolves. "You may die a hundred deaths without a break in the mental turmoil. Or, you may keep your body and die only in the mind. The death of the mind is the birth of wisdom."
@dekay.....Why do I get the impression that you're Not refering to small mammals? ;)
I'm allowed to 'watch' all I want, too....
I'm NOT allowed to get grabby, drool, or whip my head about in public to verify what I just saw...;)

My cardioMD told me to stay away from sildenafil.....
"Lasts too long...I don't want you to waste all of our expensive handiwork."
So...timing and...'co-ordination' becomes a major factor. Into the Blue...;)

We work in wood, so have 'toys' basic to esoteric (a Prazi-equiped Bosch worm-drive saw, anyone?).  Metal and plastics are part of my skill set.

Jack of all trades, master of some.  Find quantum physics adorable; makes sense of the senseless, and something to place blame on.

Spouse gave me a t-shirt lately:

Free Contradictions! $1

It's a Life. *G*

Next....
All of the above. 1500 bottle wine cellar, frequent tastings, bottle variation even with the world's finest crus of same producer and vintage, many more vagaries in viticulture than audio engineering. And let's please not even mention any aspect of human relations, which are not, ahem, "hobbies." But tweaking an audio system can take forever, as the Nth degree recedes endlessly, "boats against the current." Unless you're millercarbon, who has got everything right, a fact I acknowledge with the greatest respect and admiration. What's left after that but to read The Brothers Karamazov in Russian, Tale of Genji in Japanese, Proust in French?
You think audio can be expensive 
Track days in my old Porsche 944 Turbo S
But I love it!!!!!
Photography can be a never ending pursuit of hardware, software, and and infinite sequence of layers.  I have been doing it asa hobby for over 60 years--about as long as I have been pursuing that "most satisfying" sound.
Motorcycle riding Ducati and BMW
racing cars 
instructing hi performance driving
woodworking
tennis
skiing
mountain biking
photography

Collecting vinyl albums! Especially when you get them at 45rpm.  You need an album for each side of a regular Album.

JD


@winoguy17

Wine? You don’t say. Well, me too - North Rhone, Burgundy.

Also DIY audio.
"Even though color is the mainstream preference, monochrome may be making a comeback...
Remind you of anything in audio?"
Vinyl, of course.
I also got a kick out of dekay's answer. Although, squirrels was code for "chippies.
I started to say, "sex", but- with all the new, designer diseases out there, it’s now more of a spectator sport.       SO, yeah- porn and Harleys, +1 each.       Then again; I have known people that made collecting diseases SEEM like their hobby!       Kinda went with the Harleys.
@twoleftears We have a saying at our local camera Meetup Group (which is inactive now) - If it's Black and White, it's art!
Ceramics is pretty close to infinite. Humans have been making pottery for 50,000+ years and have barely scratched the surface. We have only begun to understand what happens inside the kiln in the past decades. The atmospherics are mind bending. And that is but one small arena within ceramics. Glazes, clay-body glaze interface, clay bodies, forming and shaping. On an on. 
Infinite? That's a pretty big concept. What hobbies have "infinite" variables? None, and imo not even close. I believe we are on the very, very low side of "infinite" variables (unless one wishes to play fantasy games intellectually). Of course, I do believe the OP was using the term loosely, not technically.  

When you begin to gain appreciation of the vast spectrum of performance, even when aggressively experiencing a wide variety of systems, it's a humbling experience. You realize that though the variables are not infinite, they may as well be when it comes to the various outcomes in systems and their performance. I build dozens of systems a year, and the spectrum of performance does not narrow, it widens. 

But, and this is critical to me, the enjoyment of variety is endlessly fascinating and rewarding. I spent an hour last night discussing with a manufacturer one Dip Switch inside a DAC that alters the entire performance of the DAC in several ways. It's another whole "infinite" field of variables inside the machines, as our DIY and manufacturer sector knows!  

Is that a hobby or a sport? maybe both..  ;-)

I forgot about playing with the cameras, Love my old Minolta and newer Sonys. Just love fiddling with them..

Regards
Walking under the sky, and reading a book, listening music, i dont need hobbys, except communicating with mimosa plants...

And dont laugh, it was already proven in 1925 by Jagadis Chandra Bose that plants react and think...He was voted in the 7 most important people in Bengal history and i read his book when i was 25 years old, 45 years ago...


It is NOT the same Bose that in physics is the creator with Einstein, of boson condensate and statistic concept, Satyendra Nath Bose ....2 genius in physics tough, but my Bose is also a genius in physiology....

:)

Owning Harleys. There are infinite ways to customize a bike, lots of time tinkering, and time and money on repairs.