Something a little different happens with beliefs directed towards living people.  Because the strength of conviction in belief is a greater factor than number of believers, and because it is usually safe to assume that people know themselves better than any other person, there is a natural resistance to the sort of alteration mentioned in the previous section.  The resistance is greater the more confidence the target person has in their identity, basically.  
	Lying to yourself is ineffective because you don't truly believe it.  Further, it's not as if people are consciously aware of what their actual beliefs are (unless you're a philosopher, perhaps).  So even if you have 100% confidence in who you are, if it's built on a lie, it won't work well as resistance.  "Fake it 'til you make it" does not work with this system because you can't fake your beliefs.
	It should be obvious that the better you understand another person, the greater influence your beliefs about them will have.  This is because the understanding puts your beliefs to the test, which thoroughly raises conviction.
	Normally not possible, but if there is an exceptional case where, say, I understand you better than you understand yourself, your belief in yourself is still necessarily stronger than my belief in you.  This is because of the experience of life; no amount of understanding can trump the conviction imparted by real experience.
	So, if a person has a weak sense of self, they will end up getting warped by the beliefs of others who observe them.  The weak sense of self, however, also makes such changes more noticeable to the person because lacking that internal grounding expands their internal sensory range.  So this person with a weak belief in who they are will probably end up burning themselves out trying to actively deny this influence.
	Psychology intertwines here a lot, and I'll have to leave it to your imagination for now, because it would be a very long section if I tried to cover all the exceptions and exploitations.
	One more thing, though:  none of that is the "prison of opinion".  The real prison of opinion happens when you die.  When you die, your personal reality goes with it, leaving only whatever stains it made on other personal realities.  The afterimage of you still remains in everyone who knew you, and the accuracy of that image is based on their beliefs about you.  Since you cannot provide any sort of contradiction or resistance, whatever they believe about you is your reality now.  If they believe you went to a place of eternal torment or a paradise, it is true in their reality.  There are most likely a bunch of these images at play, and they are now the primary influence on what your reality is - and there is literally nothing you can do about it, even if they believe you have the agency and power to do so in death.
	Of course, it's not really you.  You're dead.  It's just the most "you" you that exists now.  So it effectively is you.  Well, what's the non-personal reality?  There could be a hundred different beliefs about you.  They can't all be reality within the same space (plane of existence); there has to be one.  That one reality is basically a mish-mash of all of those beliefs, according to a compromise of beliefs.  Only, no person can actually observe the resultant reality.  As people talk about you (if they talk about you), they'll gradually share their beliefs with others and the ideas will intermingle as I've described previously.
	For the average guy, this doesn't matter all that much.  A folk tale about a giant man could eventually have enough belief to generate a giant skeleton as proof.  But that won't happen as long as the person the folk tale is about is still alive.  A hero can gain supernatural ability in response to people who believe in him.  If it gets wild enough, he could be resurrected after death.