What is the difference between gustarse and caerse bien?

A person on another question and answer forum website had a question about the differences between gustarse and caerse bien and the answers stating the differences shocked me. Caerse bien is a strictly non romantic way of telling someone “I like you.” Gustarse is usually (but not always) a romantic way of telling someone “I like you.” Is this really true? I don’t recall very well if my High School Spanish Class covered this.