Ignorance is bliss. JW tend to believe that they will survive the great A, which is always imminent, and that they have the solution to most of life's problems. A person who believes they have that solution without carefully examining the teachings may be truly unaware that this is all built on falsehood.
On the other hand, the burden placed on them by the WTS is too great a stressor and many times it robs them of life's simple joys, such as gathering with family without restrictions or associating with neighbors and people at work. Add to that the treadmill of activity, and the constant pressure to do more, then you have one very tired, unhappy, socially inept person who fools himself into believing that JW's are the happiest people on earth. Smile