I dreamed of tying a tie for myself last night, and I tied it quickly, little bow tie. And the train passed by and saw my old classmate. What does this dream mean?

Tie yourself a tie: it symbolizes your desire to succeed and show yourself. A tie is a symbol of solemnity.

Train, old classmate

This will be analyzed in detail. What kind of old classmate is this?

Perhaps, you have met an old classmate now, and his situation has aroused your association, thus having this dream.