When it comes to expressing the concept of "just knows," there are numerous synonyms that can be used to convey the meaning effectively. Some of the most common synonyms for this phrase include "instinct," "intuition," "inner voice," "gut feeling," "sixth sense," and "hunch." Each of these terms suggests a sense of knowing that goes beyond conscious thought or rational analysis, and reflects a level of awareness or perception that seems to come from within. Whether you use one of these synonyms or the original phrase "just knows," the idea remains the same: sometimes we simply know things without being able to explain why.