Huh? You don’t simply inhibit adenosine, it’s one clock-keeper among many that affect your circadian rhythms. Adenosine tells your body that you’re tired and need to rest, but it is also a timing mechanism. If your body thinks it’s morning because of the chain reaction caused by caffeine, you will get a cortisol spike at 1am and that’s it for the night, you sleep is screwed.
Caffeine will affect different people differently because of genetic variation, but there are many people who can have an espresso for lunch and that will keep them up past midnight.