Talking about feelings is generally the most transparent degree of self-disclosure. While benign falsehoods are prevalent, your language implies that the truth is always the preferable course of action. If you want to know more about someone, they'll tell you what they think about yourself and others. The next level of self-disclosure is physical appearance. You can learn a lot about someone by observing their behavior together with knowing some basic information about them. For example, if someone is very quiet in a group setting but talks openly with you one on one, they must be telling the truth when they say they're not really a social person. Conversely, if they seem too eager to make friends, they may be hiding an ugly personality trait. Finally, there's intellectual property. This includes any knowledge or skills that only you possess. For example, if someone asks you a complicated math question and then does something with numbers on the side of the house they're trying to fix, they must be looking for a work around. They could also be cheating players who want to win at dice games without being detected. In general, don't be afraid to reveal something about yourself. It usually doesn't hurt anything good enough to keep you hidden from view.