Interesting post.
Are we talking when he fell in love; or when he realized he is in love???
What P said in court was probably right to a point. He did make Y realize that what he feels for arti is love. Remember at the park when Y had gone to talk to P about the watch, P told him to close his eyes and the person who comes infront of him is the one whom he loves etc...That is when we all had discussions that you dont need to close your eyes but open your eyes to see the person whom you love. Isn't that when he starts seeing her everywhere and when vidhi finally showed him the picture, he accepted it and put up the photos...
He realized his attraction towards her starting mumbai, but would not accept it at all. Then during his bday and post bday he started accepting her as part of his life and only then did he start accepting his attraction towards her. That is when we got all the suhana day and kc etc.