Longing

Whenever I am in public without my daughter and there is another baby or small child present I become totally distracted and can't think about anything except how long until I see her again, how long until I hold her and kiss the top of her head. I finally figured out today that this is because, for so many years, every time I saw a child my son's age (at the time - whether it was 2, 4, 6, etc.), I would imagine, daydream really, what it would be like if he were with me at that moment. If I was at a tourist attraction, would he be enjoying it? If it's the women's restroom, how old would it be before I let him go in the men's room? If it's in a store, how would he behave? What would it be like to pick him up and hug him?