Well, I'm neither a believer nor a non-believer. I'm agnostic.
  But I *did* spend some time in a monastery in my mid 20s [I had
  convertitis to Eastern Orthodox Christian] - and one night I
  'got' the Trinity thing. Had similar experience with QM but that
  was as a teenager doing a book report.

  Once it makes sense, it makes sense. Doesn't have to be true for
  me, just comprehensible.