とても大きいので小さいことを気にしないと思っていたって英語でなんて言うの？

「象とても大きいので小さいことを気にしないと思っていた」＝ an elephant is so big that I didn't think it would be scared of something so small / an elephant is so big that I didn't think it would be bothered by something so small / an elephant is so big that I didn't think it would be bothered by something as small as a bee

「象はミツバチが怖いらしいです」＝ elephants are scared of bees

ボキャブラリー
「象」＝ elephant
「大きい」＝ big / large
「気にする」＝ be bothered by / be scared of / be worried about

この場合、次のような言い方ができますよ。

ーI didn't think they would worry about something so small because they're so huge.
「とても大きいのでそんな小さいことを気にしないと思った」

ーI heard that elephants are scared of bees.
「ゾウはミツバチが怖いそうです」

ご参考まで！