Many people are lonely despite being happily married. Why does this happen and is this a clue to our true makeup?

This is quite true and more common than people like to admit. It is not because people are inherently shallow and unfaithful, although there are people of that sort who are lacking in their ability to form close and lasting ties with others, the yearning people feel again traces back to the basic dilemma of disconnection. Equal to the void left by being disconnected from the divine is the extreme contrast between the plight of a physical human in a state of isolation within a physical body and only connected energetically in a subtle way with others through a meager intuitive link. Whereas the light being experience includes not only boundless opportunities for friendships of a quite deep and long-lived nature, often traversing billions of years, but the reality of existence for each soul, a twin flame conceived and created to be a loving companion for eternity that is the perfect match in all particulars for tremendous joy, enrichment, and an eternal existence of bounty and endless fascination and enjoyment. Those human beings walking around in the physical are not doing so with their twin flames because they are here on a life mission to overcome the problem of evil and not to live in bliss. So having their twin flame in their lives would be an overwhelming distraction and people would be totally preoccupied and focused on their great love and would be much less able to be a warrior for the light in ways requiring any kind of sacrifice to once again be distant from their twin flame for a time to carry out some kind of project involving hard work and a full-time commitment. This is not to say humans are selfish after all, it is more to introduce you to the reality that you are living a meager existence in comparison to the grand future that awaits you if you are successful in reaching the goal of solving the problem of evil once and for all. The end result, once humanity is healed and the interlopers removed from the Earth and under a more prolonged healing journey, will be a grand ascension for humanity to higher dimensions. That will not happen until all receive healing and all are ready. We see this taking two more generations and only if the interlopers are first removed to allow healing to go forward in a more accelerated fashion than is possible currently.