Why do we dig in the dirt, Is it an addiction?

[Bevman]

I always thought it was because I liked to know where my food came from. I thought I could do it better. I could grow things not in the stores and they would grow till the are fully ripened. I have lots of other thoughts about why I do it, but now I find out it was because I was hungering for my fix. Yes, that hunger to smell the good earth and inhale the microbes.
So not only do we spread the fig addiction here, but the soil addiction too.

http://www.gardeningknowhow.com/garden-how-to/soil-fertilizers/antidepressant-microbes-soil.htm

[Kelby]

I dig in the dirt because there's only two things in life money just can't buy: true love and home grown tomatoes (and figs).

[jkuo]

I find growing things therapeutic. When I get stressed out, I head out to the garden and start feeling better. IMO, physical activity and greenery are good for the soul. Having tasty fruits and veggies is an added bonus.