What Is Bliss?

"To direct the mind toward the basic unity of all things and to divert it from the seizing of differences -- therein lies bliss." Tejo-Bindu Upanishad

Bliss has always sounded to me like an out-of-control emotion.  But, the dictionary defines it as:  perfect happiness or great joy.  Why do we as humans seem to shy away from feeling perfect happiness or great joy?  I think it is because we are too trained to "wait for the other shoe to drop".  We are too afraid to allow joy because we fear that it will be snatched away from us.  But, did you know that the phrase, "wait for the other shoe to drop", comes from the early Irish immigrants who lived in tenements, and - when they were going to bed at night, if they heard one shoe drop onto the floor above them, they knew that the noise would not stop until the other shoe dropped -- that they probably could not drift off to sleep until they heard the second shoe drop on the floor above them.  It did not mean that bad was inevitably going to follow good.  It simply meant we have two feet, and if we take off one shoe, then another will be taken off as well.  Let us let go of all beliefs and habits that prevent us from experiencing full joy.