Prior to Jane's visit to his rented room, Sanji had been dreaming super weird and scary dreams. Usually, when he got nightmare, he would just pray or chant some enchantments if it was related to some astral beings. However, none of his methods worked and he kept dreaming the same things over and over again, which resulted in him waking up five to six times in a night with his body drenched in cold sweat.
What did he dream about?
The same thing was he dreamed himself falling down and broke his bones. At first, he just fell down from his bed, nothing was broken and he didn't think of it as anything.
In his second dream, he fell down from a second story house and he broke his legs. This time, he woke up with cold sweat dripped from his forehead. The third time, he fell down from the third floor of an unknown building, and surprisingly he didn't die, but he broke his backbone and legs.