Yep, and the logical chain itself can often be pretty clear where the discrepancy lies. In order for it to have a noticeable effect, you'd need to be looking at people smart enough to correctly identify circumstances that will make them happy in advance and then be able to influence things in average more than factors outside their control influence them. I don't think most "smart" people are more smart than life is random, without even getting into how common the requisite level of self-awareness is.