I would personally lump both head start and luck into opportunity. Opportunity can come from many things. It basically just means an open door instead of a lock

I would personally lump both head start and luck into opportunity. Opportunity can come from many things. It basically just means an open door instead of a locked door. I think it encompass all environmental factors such as class, education, upbringing, genetic lottery, connections, support network, citizenship, gender, ethnicity, economy, unsolved problems, unaddressed needs and on and on.