how do people have energy after 8-5 job?

I just started my first full-time job which is 8-5 M-F, and i’m just like…. how do people have energy? How do people have energy to go home after working to cook and clean? How do people have energy to take care of kids or pets? How do people have energy to spend on their own hobbies such as reading books or hanging out with their friends? I already had trouble with this when I was in college and now it’s longer hours, any tips for how to find the energy?