It is not necessarily true that when you can't get a person out of your head, it means the other person is also thinking about you, according to psychology. While this notion is a common belief, the reasons behind someone's persistent thoughts about another person are more complex.
The inability to stop thinking about someone can stem from various psychological factors, such as attraction, fascination, or even reminiscence of a lost loved one. It may be a sign of developing feelings or an emotional connection, but it does not necessarily imply that the other person is reciprocating those thoughts. The human mind can fixate on individuals for a variety of reasons, not all of which are directly related to the other person's state of mind. The persistence of these thoughts can be influenced by individual differences, past experiences, and emotional needs, rather than being a reliable indicator of the other person's thought patterns.