To your point, you can blow through damn-near anything pretty quickly now. Now I actually find myself problem-solving for nearly 8 hours every day. My brain feels fried at the end of the day way more than it used to.
I used to be like: "well, this thing will take me at least half a day, it's already 16:00, so I'll better do something quiet to cooldown to the end of the day and tackle this issue tomorrow". I'll leave the office in an regular mood and take the night to get ready for tomorrow.
Now I'm like: "17:30? 30 minutes? I have time to tackle another issue today!" I'll leave the office exhausted and take the night to try and recover from the day I had.