It is exactly like this: every task that a person enjoys is a source of entertainment for him and refreshes his mind. But where a bet is placed on entertainment, instead of refreshing the mind, the same task leads to stress because he has to win the task or else he will lose. You can take an example of this like this: when there is a cooking competition in which a bet has been placed, a person cooks a meal, he is mentally stressed so much that if I lose this competition, then I will definitely have to pay from my own pocket. Therefore, he has to win this competition at all costs and if he loses, he will lose.