Juggling five balls is just like juggling
three, but with two more balls.
This is not as trivial a comment as it may sound. Four Ball juggling is intrinsically different from three ball juggling. Odd numbers and even numbers of balls are juggled differently.
With three balls, there is one ball in the air at any given time. (well, sometimes two, technically, when an exchange happens) With five balls, there are three in the air. (and sometimes four)
This makes it, obviously, much harder, and therefore more impressive. Not nearly as impressive, though, to the common man, as some idiot juggling three chainsaws. If all you want is attetion, go light yourself on fire
Learning to juggle five balls is a long process. It took me two months, but I was completely obessesed at the time. If you are a more sane person, who wishes to take time out for things such as work, social interaction, and urination, you should give it about a year.