Why does the mind wander?

The following is an excerpt from a samvaad (dialogue) session with Acharya Prashant.

Questioner (Q): Why the mind wanders when we sit to study? How to control the mind?

Acharya Prashant (AP): What’s your name?

Q: Aman.

AP: Aman is asking, “How to control the mind.” What he is saying is we sit down to study and the mind wanders here and there…