&gt; <i>Once I caught up on my sleep something funny started to happen. I would only sleep about 4 hours, then wake up for 2 hrs in the middle of the night</i><p>Some are convinced that this was our sleep pattern before electric lighting was a thing:<p><a href="https:&#x2F;&#x2F;en.wikipedia.org&#x2F;wiki&#x2F;Segmented_sleep" rel="nofollow">https:&#x2F;&#x2F;en.wikipedia.org&#x2F;wiki&#x2F;Segmented_sleep</a>