The first Shia Imam, Ali ibn Abitaleb (AS) told one of his closest companions Komail:

The people are in three groups: 1) The first group are the devout scholars; meaning scholars who teach the people according to the Divine Education. 2) The second group includes the learners of knowledge including students and listeners. 3) And the third group of the people is like mosquitos and they are always adrift in wind and storm and follow any sound, and move with any kind of wind; they are not enlightened from the light of knowledge, and have not taken refuge in secure shelters [1].

[1] Nahjul Balaghah, Wisdom 147.

Source: en.shafaqna.com