Sleepy after coffee?

It’s noon now, I woke up in the morning and not doing many things had two cups of coffee. And I almost fell asleep with my head on the table. Such situation is nothing unusual for me. I can have coffee in the evening before sleep and sleep well after the coffee. I like coffee mostly because of its mildly bitter taste which together with milk is delicious for me. Is there anyone else experiencing such funny or weird effects of things that are supposed to work differently? Just curious, if anyone wants to share it will be interesting.