I have heard different theories on what it means... I have 3 (or four... Ack, can't remember....that's horrible! Lol) with interlocking swirls, at or above eye level. All of them are very smart, very sensitive and "intuative" when it comes to my mood. They are the gentlest of my horses and have been described by some as "healers" ... They seem somehow wiser than the other horses, even my yearling who seems to, calmly, understand his world without having seen much of it yet.
I have heard the Jeckyll and Hyde theory too... But haven't found it to be very true when it comes to my own horses.
Honestly... I think horses will be whatever we believe them to be... So I am very happy to believe they are kind, gentle, healing energies come to help me in life ... They never seem to disappoint LMAO
(yes, I do sometimes find myself avoiding black cats, ladders, cracks in the sidewalk, and the witching hour