hobby n. , pl. -bies . An activity or interest pursued outside one's regular occupation and engaged in primarily for pleasure.
Well, sex and booze rank high on my list

My vocation is electronics and computers... it's hard to separate work and play sometimes. In my younger days I was an avid woodworker and home remodeler, but not so much lately. I still tinker with car repair too... it's satisfying to diagnose the problem and fix it, and not paying a mechanic a $1000 to replace a $100 part makes me ecstatic. But the work itself is not as satisfying as it used to be since you now have to tear apart half the car to replace a simple part... not to mention the special tools required. Why any car maker would put into production a design that require removal of the turbo and exhaust manifold to gain access to an emissions system vacuum control solenoid is just beyond me. Nonetheless, these are all things I enjoy doing, but are more acts of necessity rather than "just for fun" hobbies.

 Gardening is a different story and is purely for my own enjoyment. When I lived in New Jersey I had specimen Peony and Rose gardens, many unique Azaleas and other Ornamental shrubs in my landscaping, and a nice vegetable garden. Since I moved to the desert (where almost nothing survives the heat of Summer) I've lost a lot of interest... peonies, azaleas, etc. won't survive here and tomatoes raised here don't taste like tomatoes. Annual flowers (petunias, snapdragons, etc.) do well here in the spring and fall, but its hard to make a hobby out of that. I do still have about 2-dozen varieties of Christmas Cactus (which spend the May - August indoors and Sept - April outdoors). I have also been experimenting with some plumeria the past couple years... they are tropicals and need special care since they stress when it's above 110F (which occurs frequently in July & Aug) and are not freeze tolerant (it was 21F here last week) so they need protection in Winter. I'm also trying to raise a mango tree (mangoes are not freeze tolerant) but the recent freeze may have terminated that endeavor .