The caffeine trap can be particularly insidious, especially for those of us who metabolize it slower. Its half-life can range from as low as 1.5 hours all the way up to 9.5 hours.<p>So on the high end of that scale, if you drink 3 cups of coffee, containing say 300mg of caffeine, between 7 and 10 AM then you still have around 100mg of caffeine kicking around in your system when 11pm rolls around, clogging up your adenosine receptors and disrupting your body's ability to signal to itself (and you) that it wants and is ready for rest.<p>[<i>And if you don't follow any sleep hygiene practices, you are also probably depriving the body of its primary mechanism for initiating the sleep processes. You can take supplemented melatonin but it is usually only effective for short or medium-term use, and in my personal experience is way less effective than the home-grown good stuff produced in the pineal gland</i>]<p>So you lose 30 minutes here, and hour there of sleep. Not necessarily every night, but on a weekly basis you find yourself worn out, mentally ready to rest and recharge, but there is a disconnect in your brain and body that doesn't allow a smooth wake-sleep transition. The longer this trend occurs, the more sleep debt you find yourself in, the more you tend to throw in another half-cup around noon from time to time just to make sure you can keep going.<p>Worst of all is when you hit on the realization that alcohol or some other drug can help to knock you out when you're still too wired to sleep even though you really want or need it.. unfortunately (with the possible exception of a few herbs) basically every medication or drug that puts you to sleep also negatively impacts the quality of that sleep. Which in the above scenario is going to spell out more caffeine in the routine, sooner or later, to compensate further. Do be aware that this doesn't necessarily have to be conscious realization, it is an extremely easy and I assume common habit to fall into.<p>If you happen to process caffeine at a 1.5 hour half life, and can conk out like a light under most circumstances, I am truly jealous. Enjoy your God-given gifts ya lucky bastard!