BB probably never slept in his lifetime is absolutely insane.
Marco stated even that his very body structure ist strange. And Marco is a Physician.
That is strange. What’s up with Blackbeard’s body ?
In Databook it was stated that his secret lies in Ace's comment about his Age when they met
And after checking that Chapter, it seems that Ace states BB lived as twice as a Man
From first read, we thought he meant that BB is twice as old as Ace (Which is true)
But now it's obviously clear that BB lived twice as others because he never sleeps !!!!
Add to it Luffy & Zoro's Comment on BB in Jaya when they referred to him as "They" + his Jolly Roger
And in Drum Island Arc, Sanji & Luffy talked of rumors about People who can't sleep in snowy Islands, same Arc where BB was mentioned
And guess what also appeared in that Arc ?? it's Two Humans merged together, i think Oda was clearly hinting towards BB
(Oda used similar strategy when before he introduced Kaido & his Legendary Body, he hinted at such concept by introducing Funk Brothers where one of them have very Hard Natural Body)
BB's SBS Pic when he was Young was a huge Hint too
I believe that BB Theory where it says he is 3 Souls/Bodies in one is true and that's why he can't sleep, because they keep switching
This also explains why he can eat more than just 1 DF and why he can be harmed even though he ate a Logia
The real question now is, how did this happen to BB ? why was he born like this ??