Walter Mitty Meaning
A person, generally quite ordinary with unexceptional qualities, who is prone to fantastic daydreaming of personal triumphs.
This term comes from James Thurber's short story, The Secret Life of Walter Mitty (1939), describing a meek, mild man with a vivid fantasy life. The character's name has come into more general use to refer to an ineffectual dreamer.
Example: If you are a Walter Mitty with Everest dreams, you need to bear in mind that when things go wrong up there, you may lose your life.