Judging from what people seeking my advice tell me, it seems relationships fall apart for three key reasons: 1. Lack of trust: Whether because of lying or cheating, it isn't always easy to restore trust once it's been compromised. When it gets to the point where you simply can't confide in the other person, the relationship is doomed to fail. 2. Lack of communication: Problems in the relationship that stem from a lack of trust (see #1) can sometimes be resolved when people put their feelings on the table and are open to compromise. But when even open communication isn't feasible, it signals that the relationship may be on its last legs. 3. Getting too lazy and comfortable: Once we've been with someone for a long time, it's normal to become complacent in the relationship. Gone are the days when you worked on your physique to impress your partner and surprised her with flowers and candlelight dinners. In order to keep the relationship from stagnating, it...