How do people work the same job 9 to 5 for 50 years till they turn 60 and not go crazy?

I'm just 24 and 2 years into the workforce, and I'm already tired. I don't know how I'm supposed to spend the next 40 to 50 years working 9 to 5 and just waiting for the weekends. It's just an endless cycle of just existing to work. I really don't understand how people work a 9 to 5 for 50 years and not go insane. Anyone, please tell me.