Love at first sight, AKA "the thunderbolt", for anyone who has seen The Godfather.
I've experienced it on one occasion, unfortunately, it didn't last. She's now married to a vet, who she technically dumped me for, and she is one of these people who bombards Facebook with pictures of her two children she has had with him.
In fact she wrote to me about 2-3 years ago to say that she regrets making a more boring and sensible choice and that she misses my humour and independent mind and that she wishes she had given us a proper chance.
I don't know if she was wanting some sort of reconciliation, fling or going through post-natal depression.
But yes, the first time I saw her, I felt like I had been kicked in the head, in a pleasant way. Probably not the most appropriate simile.