If you read my post, it say "clueless about parenting". Parenting is not an intellectual exercise even though it is important to use your brain while doing so. Parenting is a visceral heart wrenching experience that engages one's whole being. Prior to raising our two children both my wife and I were involved with other people's children for a decade. I taught elementary school and she was the director of an infant through kindergarten child care center. In addition we had our nieces too. Being a parent is not at all the same as time and effort with other people's children.
It is similar to the situation faced by anthropologists when the spend time with an unknown primitive culture. If they observe and take notes and live along side the people they are studying, they will have a pretty good idea of what life in the village is like. But they will not know what it is like to be a member of village. For that they have to put aside their note pads and immerse themselves into the village life and live as member. They have to lose all objectivity. Parenting is like that. Until you immerse yourself in the reality of living the life of a parent, you are on the outside looking in and taking notes.
Your experiences will be helpful when you do become a parent, but they are nowhere near the same.