Imagine you and your friend are playing a game together. Both of you want to win the game, but you have to make decisions that affect each other's chances of winning too. A Nash equilibrium is a situation where neither you nor your friend can make a different decision to improve their own chances of winning. In other words, you've both made the best decision possible based on what the other person is doing. It's like a stalemate in the game, where neither of you can gain an advantage by changing your strategy.