The other issue here is that when Fleurista - and others - talk about perception, several different kinds of perception at are issue but often seem to get mixed up.

First, there are the perceptions each individual has of the world & other people in it. Which, as you note, can come directly from our senses and also through cognition or thought processes.

Sometimes due to injuries or anomalies, our ability to perceive through our physical senses and/or our ability to correctly process our sense perceptions cognitively gets altered. As a result, our perceptions can be dulled - in the case of someone who has nerve damage or has suffered burns - or they can be heightened - as in the case of many people who've lost one of their physical senses (such as people who are blind, deaf or can't smell). At the same time, some people have senses that are extra sensitive or have special features - such as people who have "sophisticated" palates, can pick up smells that other people can't, or see colors when they hear music.

Second, there are the perceptions each one of us as individuals have of our own selves and our bodies. Which again come from both our physical senses and from thought processes.

Third, there are the perceptions each one of us has about how other people perceive us, themselves and the world. IME, the way we perceive other people's perceptions is more about our own thought processes than about our usually reliable built-in senses like sight, smell, taste, touch and hearing.

A lot of people make assumptions about how others perceive them that have little or no basis in fact because it's very common for humans to project our own perceptions, inner feelings and beliefs onto others. Also, a certain segment of the population has always been susceptible to assuming that they way they personally experience & view the world is the way all human beings do. But in truth, other people often don't actually see us (or the world) in the way we think they do. Lots of times individuals are utterly convinced others see them in a certain way when, in reality, others don't see them that way at all.

Moreover, many people think that others must think X,Y, Z about them when the truth is that those others often have never paid them much mind or given them any thought to begin with. To paraphrase a famous quote, Most other people don't think ill of us - they don't think of us at all. In our own minds, we are in the starring role, but in other people's minds we often aren't even bit players - we don't even register in their perceptions.

TL;DR version: when people speak of how others perceive them, or how they are perceived in the world, what they usually are referring to is how they think others perceive them and how they believe they are perceived in the world. And in these cases, there's usually a whole lot of projecting and assuming going on.