Connect Four might be a game that triggers childhood flashbacks, but it's not simple stuff. In fact, Numberphile reports that there are more than 4 trillion unique ways to fill a standard board. But there's only one way to guarantee a win every time.
There are slightly fewer than 2 trillion ways to get four in a row, but if two perfect players are competing, the only way to lock in the win is to go first and play in the centre column. As Numberphile points out, a perfect opponent would know that they couldn't win at that point, but if they played perfectly anyway they would lose within 41 moves. Time to show all the kids in your life what's what.