Bricking it

I'm reminded of the phrase "[They] hung in the sky in much the same way that bricks don't." - Douglas Adams.

This fellow floated by as we lounged with coffee on the law.. scrub that.. grass.  The question is, how does one learn to float around under a plastic bag like this, given that there doesn't seem to be a back seat for an instructor?

Feel sure someone's about to tell me...

--
22nd pint of essence-of-cheeseminer was extracted earlier this afternoon.  There really can't be much left in there.  Unusually I'm feeling a bit zonked as a result - the hot weather isn't helping - so doing some exhaustive lounging this afternoon.