Starbucks - the gateway drug...

When I was in my 20s I was basically the bald character in Dilbert that said his purpose was to turn coffee into urine (I still have that cartoon somewhere...).

As with alcohol, how our bodies react to depressants and stimulants changes over time and what we eat and drink in general.

I'm also over 50, and have found that taking in caffeine less than 10-12 hours before I normally go to sleep affects my sleep and going to sleep in ways it didn't years ago. Since we also get up early (5:00 or earlier usually), my wife and I are getting ready for bed before 9 pm. Watching my caffeine intake is just another adjustment to make in life.