When I was a baby, it was back in the network only TV days. (just a few years ago...) In the early morning, before the news started on one of local stations, they turned the camera on an aquarium and just broadcasted that for a half hour. My folks would plunk me into my little baby seat, toss me a bottle and set me in front of the tube while they showered, etc. Apparently I was happy as a clam and they were able to have that time to start their day peacefuly. I don't know if it has anything to do with my habit, but it makes sense. I could sit for hours and watch my tank. I find it relaxing and occasionally inspiring, and there is always something more to learn about my fish and their behaviour.
As a youngster, my dad had a small planted tank. Overstocked and algae-ridden... (Mainly because my sis and I kept insisting on picking out the fish and Daddy just couldn't seem to say no). I loved that tank, but it is the reason I have (until I stumbled on this site and you guys created a MONSTER!) always used silk/plastic in my tank. Until yesterday! (Waiting for the flourite cloud to clear, but SO excited to have finally gotten up the nerve to go for it!)
I don't know if it was the early aquarium babysitter that sealed my fate, but I absolutely adore my aquariums. Fortunately hubby does too, although he just watches and occasionally winces (but surprised me yesterday with a new heater, new filter and a couple different thermometers to try out!!!)
There are definitely hobbies that are more expensive and/or detrimental to well-being out there!