How do you know he/she was worth it? Is he/she still worth it?

you know this person is worth it by one look between 2 people when its soo intense you dont even realize there is anyone else in the room everyone else disappears its just the 2 of you if you feel that when you look at the person you love and they look back the same way then thats how you know even if they are hard to read thats how you know there worth it.