When I talk about energy I mean the sugar the brain consumes, not how tired you feel, or the effort you must give. There is plain no difference in the human brain if thinking about mainstream or not, it still consumes a lot. Not thinking , and just listening, is much cheaper. This is why being a social species is a saving of energy: one thinks, all the others just listen. Doesn't matters what you think exactly, if mainstream or not, the energy consumption is still the same.