Coffee used to work for me. Since highschool, and evem through college.
After college, I just stopped drinking coffee but today, I had two servings and even though I feel more focused, I am mentally tired and yawning.

I am just 24 too. I usually sleep between 11-12pm and I am already sleepy.
This is unusual to me because coffee usually keeps me up at night quite easily. Yet now, I already feel like I can sleep and I didn't do a lot of manual labor today either. Is this normal?