It sounds like a silly question, "Why do you garden" but I feel like a lot of us probably have one or two very specific things that got us involved in horticulture and/or agriculture. Share your story if you've got one...
For me, I would say the #1 thing that got me interested in gardening was my grandfather. He passed away from lung cancer several years ago but I think he would be proud of me for not only gardening for myself but pursuing it as a profession (I manage a research greenhouse). My fondest memories of him were helping him pick green beans or lift potatoes in his garden. If I grow old to be half the man my grandfather was I'll be happy with who I am.
My mom is also an avid flower gardener. My parents house won "yard of the month" from their HOA so many times they were asked to join the judging panel to render them ineligible and give someone else a shot at winning. She was also very supportive of my early gardening including driving me to the store to buy parts to build hydroponics systems before I was old enough to drive and helping me install a modest raised bed in the yard to grow a few veggies. I think her investment paid off because now the student has become the master.
What about you- why do you garden?