It means that when somebody's away, someone else misses them and likes them more when they return. For instance: a person you're dating goes away on a business trip or something. While he/she is...
It means that when you don't see someone for a long time, you miss them more and more every day and remember mostly positive qualities about this person.
It means that when two people who care about each other are apart (absent from each other), they begin to miss each other and realize how much that person means to them. It can also be compared to...