It depends on the circumstance. I'm also from a poor background in a third world country (so super poor by Western standards), and although I did work both very hard and very smart, if I had not moved to a first world country there's no way I would have achieved much. Sometimes your environment can make it that hopeless, and I've seen it in many of the younger people back in my home country now. They've essentially just "checked out" of society, which leads to higher crime and unemployment overall.