A method and systems for reminding a user about personal objects that should be carried or should not be carried, depending upon the user, the date and the time and other parameters. In the system, a radio frequency identifiers tag identifying each personal object is directly attached to the object. All the objects are listed in an object table storing the identifiers and their main characteristics. A rule table is provided having entries setting forth the relations between the objects according to four basis rules of the types "X requires Y", "X excludes Y", "X required" and "X excluded". When activated, the reminder device checks the present objects and analyzes the rules to determine which objects are missing and which objects should be absent. The user is forewarn if objects are missing or should be absent.