I don't think that being exhausted at the end of the day should be accepted, or considered normal. Sure, everyone has bad days. What happens if you're working

I don't think that being exhausted at the end of the day should be accepted, or considered normal. Sure, everyone has bad days. What happens if you're working to your utmost, absolutely everything you've got has to go into the job, and you hit a rough patch? A cold, a breakup, God forbid a death in the family. You have to build that into your routine. You're not going to be a superhero every day, so you need to spend some of your time managing for that, setting things up in such a way that when you have a bad day, you can compensate for it, rather than falling apart. If you're putting out more than 90% of your 'best day' effort every day, you're sitting in a very precarious place. You need to be proactive about resting and rehabilitating yourself.