I brought a cactus back from Sanya seaside and planted it when I came back, but why did it grow into pieces, as long as chopsticks?

Personally, I think it may be the following reasons: first, environmental differences lead to. Soil difference, the seaside is saline-alkali land, where there is sea breeze and plenty of sunshine, your place will not be the same, all kinds of differences.

Second, the leaves are inserted. The cactus has just begun to grow like this. "There are pieces that look like chopsticks and grow all the way up." When a leaf grows to a certain extent, it will be deformed and flattened, and become its mother's appearance (I have planted this before). Well, hehehe, maybe your cactus may be another miracle of nature.