to change your opinion about something or start to doubt it
have second thoughts
to create ideas or pictures in your mind
use your imagination
to make a decision
make up your mind
to give someone a piece of advice that helps them do something
give someone a hint
If an idea _____, you think about it for a short time.
cross your mind
to stop being able to think only about the thing you are doing
lose your concentration
to have an idea suddenly
have a thought