As we all know from our close reading of Shakespeare's A Midsummer Night's Dream, the course of true love never did run smooth, and that's what Wild at Heart is all about. Obviously Sailor (Nicolas Cage, wearing a snakeskin jacket that represents his individuality and belief in personal freedom [I'm looking at you, Driver]) and Lula (Laura Dern) are clearly meant to live happily ever after. Are they going to let little things like a jealous witch (Lula's mother), a beating death, a prison term, a hit team, voodoo, outrageous violence, a botched bank robbery, the first of several Cage Elvis impressions, and the craziest cast of characters ever assembled (except maybe in other David Lynch movies) stop them? Of course not.
There's probably someone who could summarize the plot for you, but that someone isn't me. All I can say is that it's hilarious, surreal fun and that while it may not be the perfect Valentine's Day movie, I can't think of a better one at the moment.