The phrase, "It's just my imagination running away with me," coming from the Temptations in 1971 in their hit song, "It's Just My Imagination," tells more truth than fiction.  Research from the Karolinska Institutet in Sweden that was led by Professor Henrik Ehrsson indicates that one's imagination is strong enough to change one's real-world perception.  He says that "what we imagine hearing or seeing 'in our heads' can change our actual perception. "