If you are observing people you don't know. the likelihood that you can positively know how people are thinking and feeling versus what they are saying or doing is increasingly hypothetical. Why? There are a number of reasons - one may be that you or me the observer may be projecting based on associative data previously observed. This becomes a game of fantasy replete with recycled thinking at its most rudimentary level. (Sri Aurobindo writes about current human inability to think in complete thoughforms due to the divisive era in which we reside).