Even though this was a song and not real life, the things that Paula sang about are totally true. Opposites can, and do, attract each other all the time. What happens after that depends on how well the couple meshes in other areas of their lives and relationships. They can be as different as night and day, but if the love is strong enough and there are SOME things that they have in common, these relationships work out all the time.
Something to consider is that people who are completely opposite from each other can, many times, complement each other. They can make each other stronger and better as people. For instance, suppose there is a couple where one partner has a short fuse with a terrible temper and the other one is very laid back and rarely gets upset over anything. The partner who is a bit too laid back can often help the partner with the terrible temper. That partner can introduce calmness and stability into the relationship. On the other hand, the partner who is so volatile can help the one who tends to let people walk all over him or her. This works out quite well all the time.