Trying to define what is bliss.
Being in moment is bliss. You are not necessarily in comfort or joy. You can be in pain but, when something is so engrossing it consumes you - and - you get a feeling of timeless-ness - that is bliss.
What i am trying to define here is very similar to concept of Flow as described by Mihaly Csikszentmihalyi
If we can find immediate next challenge - that is sufficiently difficult - that it requires our full attention. And we make it interesting so that we want to be in that moment and nowhere else . These two action can put us into a state that is - i believe - higher than just happiness or joy.