You’re in a relationship. Your happiness is a 6 out of 10. You think that you could be in another relationship which would get you to an 8 out of 10. So you end your current relationship.
But now you’re alone and lonely, and dating is hard. Your happiness is a 3 out of 10. The relationship you were in looks much better than this, and you were never firmly committed to getting to 8 anyway. So you get back together.