What other hobby...

Mono/Single speaker audio system?

Even though color is the mainstream preference, monochrome may be making a comeback...
Remind you of anything in audio?

Photography.  At least we got past the analog vs. digital debate (for the most part).

I'm into movies. To infinity, and beyond!

@robjerman,

Chess and audio and chess used to constantly battle it out for my attention.

In the end audio won out for fun value but I still enjoy watching it on YouTube.

Especially all that trash talking on Coffee Chess.

https://youtu.be/9o6muR3EfhM

Homebrewing!

golf

"I'm a squirrel watcher
I'm a squirrel watcher
Watchin' squirrels go by
My, my, my

I'm a squirrel watcher
I'm a squirrel watcher
Here comes one now
Mmmm, mmm, mmm

I was just a boy
When I threw away my toys
I found a new pastime
To dwell on

Whenever I detect
Members of the other species
I play the game I do so well, oh

I'm a squirrel watcher
I'm a squirrel watcher
Watchin' squirrels go by
My, my, my

I'm a squirrel watcher
I'm a squirrel watcher
Here comes one now"

DeKay

HO Model Railroading
Gardening
Wood working

AND the greatest hobby of them all;

Retirement, is the greatest, sport, hobby, and THING ever invented.
Too bad it took me over 45 years, to figure it out..

Favorite animal.... Terriers, and Hummingbirds, Both just like me. ;-)

Regards

Right. They all do. Any time anything seems simple, look around, you're missing something.

Auto detailing.  Guys will spend thousands on 1 tub of wax. An infinite number of detailing products on the market and the enthusiasts are just as vocal about what is snake oil and what isn't. 

Audiogoning. 😊

Chess!

Gardening.

Collecting stamps.