Paul - I think I have been connected with my spiritual being for a long time, but the connection has deepened as I have got older. I had cancer 10 years ago, and had to face the possibility of death, and ever since then I have looked at life differently.
While any of us could have an affair, I am not sure that we could all have a MLC. I have just read a book 'The Search for the Real Self' by James Masterson. It is not a book of pop psychology, and while I don't fully agree with all it says, the central idea is that the more that we are touch with our true self the more easily we deal with what life throws at us. People who operate with a partial or full false persona are much more vulnerable and fragile, because they have a distorted view of their reality. Narcissism, which plays a big part in the MLC is particularly tricky, as the person has a grandiose sense of themself, often hiding behind an apparently quite unassertive exterior.
I am not saying that people with a propensity to MLC are better or worse, just that they are less well integrated. I was brought up in a loving family where people talked about their feelings, and loved each member for who they were. Many of the people here have that same sense of stability. We attract the more fragile people like moths to candle flames.
I think cases like yours where both partners have MLC are rarer, but I could be very wrong!