Most Helpful Guy
Sometimes, you will be in a relationship and it won't work out but you will come away being a better person because you learned from the person or you learned from the experience. Often, others will look back on those occurrences and try to rationalize them by saying, "You were meant to get together but you weren't meant to stay together." That's similar to what you are asking about.
Most Helpful Girl
Some people can fall in love but certain circumstances mean that they cannot be together, you can still love a person without being with them, sometimes a relationship full of love just doesn't work because the two people are too different, doesn't mean they don't love each other. I loved someone when I was younger who was so bad to be with, he cheated, manipulated and lied through three years but we did love each other but it just didn't work. Sometimes people fall in love whilst they are with someone else and that would also be relevant to the statement. Love comes in all shapes and forms, not just the love between two people in a relationship. It's so complicated but you just know when it's right and real.