Early morning swim

I woke up early this morning my regular 4:30am swim in the overly warm 2 lane health club pool and was shocked to find it nearly full.  Given the large variation in speeds that exist in non-swim club scenarios, circle swimming is awkward at best and usually avoided.  The usual mode is for swimmers to take half a lane so that maximum number of swimmers is only 4 in a two lane pool.  I jumped in to occupy the 4th and last available slot.  Minutes after I started, another swimmer shows up and has to wait.  I am pretty sure I was the only one in the pool that was motivated to swim that early in the morning by the fear of being in shape for an eventual English Channel crossing, why were the rest up that early?  Am I in a town occupied by a bunch of insomniacs?  During my brief hour of swimming , two people had to wait for a lane to open before another swimmer finished their workout.  When I left shortly after 5:30am, the pool was empty. What is the world coming to that the "rush hour" of swimming is between 4:30 to 5:30am in the morning?