When people claim "I am in love"

I wake up early in the morning to see my friends status: sunflower loves rose....
well I know she is sunflower n he is rose... The guy she met once, claimed he was her soul mate, then she said she is crazy about him and finally today she admits she loves him. I come to hear all this in two weeks... Though she had been talking to him for a long time. Say a few months...
I think how come someone realizes they are in love in just few weeks... Or is it they realize n don't want to make it open... If I was ever in love I would post it on every wall in the city man I am love...
Well any ways happy for her....