True, and here's an interesting twist: as you wrote, this is mainly happening due to "I think", so it's primarily on a memetic level. Humans also pass on lots of thought/behavioral aspects to their children (memes). Therefore I'd expect that selection on the behavioral level is happening much faster than on a genetic level.

Idiocracy's "stupid genes win" likely won't happen, my theory is that selection will remove memes (behavioral/thought/cultural patterns) that cause childlessness from the meme pool much faster.

Could also well be that natural selection will rear it's ugly head again first. I previously thought that people rejecting the evolutionary theory (creationists etc) were just backwards and anti-science. But I've realized since that this is a too simple judgement. The ethical implications of evolution are dark. Humans have had a word for selection since the dawn of language - "death".

A bit sad that paraphrasing Paul Watzlawick in this context fits very well: one cannot not participate in evolution.