A friend once told me that before a person could jump into a relationship, he or she must first complete him or herself as a person, and that he or she must never rely on his or her partner to complete him or herself.
To expound on this, before you get yourself involved in a relationship, you must first establish yourself fully as an individual, and not be dependent on your partner to complete you as a person. Think of you and your partner as two pillars, and your relationship as a plank that you both must support to create a strong, efficient and sturdy bridge. You and your partner as pillars must first individually build yourselves strong and sturdy. Pillars do not fill each other, instead, they complement each others' strengths. Hence, with two strong pillars, you both make a strong and long-lasting bridge.
There is an amazing "I/me" and there is an amazing "him" or "her". Put them together and you both make a super, phenomenal "us". Couples are teams of two super individuals. They work together to achieve great things as well as to keep their relationship strong. People do not complete people the way dentures fill the gaps of an old person's teeth. People join forces to make a dynamic couple.