How Much Sleep Have I Lost?

Sleep is not static in our lives, or does it change as we it does change as a function of age. The 90 minute cycle largely remains, but the distribution of that sleep is differentbut let so that's so your night goes in these 90 minute cycles of nonrem and rem. But thre's even an interesting difference within that 90 minute cycle. And there are consequences to this. If you're short changing yourself on that dream sleep, there are consequences.