Will someone explain to me the phenomena of when a girl talks to a guy and immediately catches feelings for him and then he admits he also has feelings for her, she loses all interest in the guy

Excerpt from the trip of a lifetime elizabeth mohn 3 a little more than a week ago, my mother and father started packing our suitcases to prepare for our trip. my entire family woke up early sunday morning, packed the car, and began our expedition to niagara falls. when we reached the american-canadian border, i was excited to enter a foreign country for the first time. the third paragraph is mainly about a) traveling to niagara falls b) leaving the hotel. c) seeing the falls. d) returning home.