When I was in my 20s I could have a triple shot machiato at 10pm and be asleep before 11...
Now, I'm spitting distance from 40, if I have a 3 to 1 mix of decaf to full fat coffee made with a drip filter (edit: past noon) I'm up til 3am....
I recently turned 40, and we've switched entirely to decaf. I still drink it because I love my latte, but now I can make a latte with dessert and don't have to switch out anything. I use a Miele automatic.
I have one cup (travel mug, so probably about 600ml) of full fat coffee in the morning, then one or two at 4-1 decaf - cafe before lunch as even on a hot day I love a hot coffee. If I make a brew anywhere near noon or beyond it's full decaf, again because I just enjoy the taste, and having a nice warm drink.
I remember a few months ago someone made a post basically calling out anyone who drank coffee as an addict. And yeah, I suppose there's a bit of truth to that, but I'll get absolutely unbearable to be around if I don't have a smoke, but there's sometimes weeks where I don't have any caffeine at all, and I'm completely fine.
My workplace took out all the coffee machines, so I’m stuck with expensive coffee all day, and then get back to my coffee maker at home late enough that I shouldn’t be drinking it