on one's mind
nag
leap to mind
persistent
haunting
spring to mind
cross someone's mind
hang
train of thoughts
stream of consciousness
stir
recurring
circuit
come to mind
perseveration
intracognition
live rent-free in someone's head
think about
daydream
hammer home
brainful
tachyphrenia
brain cloud
bemused
mindful
in agreement
broody
in mind
self-involved
preoccupied
lost
intrapersonally
metacogitate
like-mindedness
recept
puzzle
internal monologue
credulity
self-debate
in one's opinion
rumination
academicism
not leave one's thoughts
ponderomotively
considerate
back up
multiplist
get ahead of oneself
use one's noggin
absorbed