When I'm off for a few days but still have plans, I realize how draggy and groggy I get. I used to think it was because I often sleep more.
Then I realized it is the caffeine!
Now I haven't been drinking coffee that heavily except over the last few years. I can go flavored or straight black. But I have to have Uganda or DeathWish, it must be heavy.
When I don't get or have it, it's a different ballgame for me, that it took me months to notice.
As I rebuild my overall system and regimen, I now know. I have heard the tales but I didn't realize I was drinking that much expresso. It catches up to you kind of like anything else. I also notice when a crash may hit me.
I try to utilize more organic energy so I'm not reliant on coffee. Many in this era are, as well as well as a lot of regular sugar, which isn't good. I consume primarily cane sugar, which gives you the kick, but reserves the crash.
So remember to monitor what you're placing into your body daily. When something is off, you definitely know.