The kind of love/infatuation you describe might also be called temporary insanity. The one so giddily afflicted is blinded to reality, immune to logic, indifferent to her own well-being, and incapable of anticipating the consequences of her actions. In most states, were she examined by a qualified professional, she would be found incompetent to sign any form of legal contract. I guess that's why we don't do such examinations before weddings.
I can't find the source, but someone famous was asked if they believed in love at first sight. "Yes," they said, "but I also believe in taking a second look."