in one's head

Prepositional phrase

 * 1)  Within one's intellect, memory, or mind.
 * 2)  Within one's imagination; without basis in reality.
 * 3)  Mentally.
 * 4)  Anxious due to overthinking an issue.
 * 1)  Within one's imagination; without basis in reality.
 * 2)  Mentally.
 * 3)  Anxious due to overthinking an issue.
 * 1)  Mentally.
 * 2)  Anxious due to overthinking an issue.
 * 1)  Anxious due to overthinking an issue.
 * 1)  Anxious due to overthinking an issue.

Usage notes

 * In the senses of "within one's mind" and "within one's imagination", sometimes preceded by as an intensifier emphasizing that the indicated information, belief, etc. is entirely and exclusively within one's mind or imagination.