I accepted the invite because natural selection has shaped the human mind to take actions that have, in our past, tended increase reproductive success.
That statement isn’t as creepy as it sounds. I did not calculate the direct reproductive opportunity of this speaking engagement. Rather, our evolutionary past means that we are inclined to pursue proximate objectives that lead to the ultimate goal.
For example, we seek status – and what could be more status-enhancing than speaking here. And we engage in the costly signalling of our traits – such as intelligence – to the opposite sex, allies or rivals.