It can represent some problem with the amygdla or parahippocampus
in the
brain. Amygdala controls present thoughts and
short term memory. The parahippocampal controls past thoughts or long term memory.
Other possibility is of ADHD(attention deficit hyperactive disorder). It typically presents itself during childhood, and is characterized by a persistent pattern of inattention and/or hyperactivity, as well as forgetfulness, poor impulse control or impulsivity, and distractibility.