Yes but that's "in a few decades" ON TOP of millions of years.

If I had to give an estimate, I would consider less the time taken to date, but the current state of our knowledge of how the brain works, and how it has grown in the last decades. There is almost nothing that we know so little about as the human brain, how thoughts are represented, modern imaging techniques notwithstanding.

> Yes but that's "in a few decades" ON TOP of millions of years.

If that's the bar, then anything else can fit in "a few decades", since that also rests "ON TOP of millions of years".