Two years for the fluid is fair enough as it absorbs moisture, but I'm guessing a lot don't stick to that.
As for the seals at two years I don't know anybody who does that, but maybe somebody who likes spending money and dismantling brake calipers does it
.
I hate spending money,
Fizzy Pies, I fear my earlier response to tomjimtom may have been misunderstood, I wasn't suggesting you like spending money, that was some fictitious person who existed only in my imagination (or maybe it's my wife?).
Also I wasn't suggesting you shouldn't clean the calipers and pistons more often, (as Deefer suggests), just that changing the seals every two years seems a bit much for normal use, imho.
P.S. If any of that doesn't make sense, then take it as a warning on the evils of drink on a young impressionable mind.