enter (one's) mind
To occur to one suddenly. After that idea entered my mind, I was able to alter the experiment and finally achieve some success.
Farlex Dictionary of Idioms. © 2015 Farlex, Inc, all rights reserved.
enter one's mind
Fig. [for an idea or memory] to come into one's consciousness; to be thought of. Leave you behind? The thought never even entered my mind. A very interesting idea just entered my mind. What if I ran for Congress?
McGraw-Hill Dictionary of American Idioms and Phrasal Verbs. © 2002 by The McGraw-Hill Companies, Inc.