The catch is self-contained. Instead of seeking for someone to care for, look for someone who can care for herself (and who wants to). In the long term, you require someone with her own set of interests and passions. You require someone who does not reinvent herself for each man she dates. The catch doesn't need a lot of attention. She knows what she wants and goes after it. The catch does not feel the need to discuss every detail of her life with her boyfriend/husband. The catch is not afraid to show her feelings.