Learn to smile.

Bilingual example:

We should learn to smile and never let blue emotions surround you and your face.

We should learn to smile, and don't let the melancholy mood surround you and write sad expressions.

Definition of keywords:

Learning: learning; Study, study; Acquisition; Remember; Learning; Recognition; To learn/hear (an event)

Smile: smile, smile; Express with a smile; End with a smile; Smile; Praise; do not care