I was formula fed...in fact, my parents were so poor that they said they would sometimes just give me whatever they had in the house, in the bottle. Regular cow's milk, powdered milk, etc. My mom was so young and ignorant when she had me, and no one in her family had breastfed. I think the only thing that's made for my decent immune system in adulthood, is the fact that I had four younger siblings, and we were encouraged to play in the dirt and we got sick so much as kids that we all have decent immune systems now.
ETA: I was born in '82....my Mom was so young that my Grandma had a lot to say about how I was fed...in her day, only poor women breastfed. My Mom says that she attempted to nurse me, but that her breasts hurt so bad, and when she would try to nurse, milk would squirt out the other side. I feel kind of bad for her--she was just so ignorant. She probably had a great supply! She says she tried again with my youngest sister, but I don't think she really gave it more than one latch-on, because she actually had me bind her breasts two days after she had my youngest sister. I was 18, and I remember thinking what a waste that was! I have no idea why, but I ALWAYS knew that I would nurse my babies, even though I had only seen one woman nurse in my whole life, and she was covered with a blanket. It was just instinctive for me.