Correct as most don't have the knowledge of their own immortality and hence they are prisoners. Just like the flea experiment where a number of fleas are placed in a bottle and the lid placed on. After a period of time the lid is removed and although the fleas should be able to easily jump out of the bottle they cannot jump higher than where the lid was! You and I know that the boundary is gone but for the flea, the boundary is just as real as if the lid were still in place and so they are trapped by their own imagination!