Getting to the highest score in the history of test cricket isn't something that happens every day. Of all of the hundreds of thousands of test innings, to be ranked as the highest is some achievement, so a changing of the guard is very rare indeed (between 1938 and 1994 it only changed once). To post an absolute great grand-daddy triple or quadruple ton, you need to be one of three things. Either a) massively selfish and happy to play a long personal innings irregardless of the match situation (see Lara's 400 not out v England in 2004), b) playing against a crap team on a road (see Hayden's 380 v Zimbabwe in 2003), or c) freakishly good (see Bradman, numerous).
Cricket is an odd game, as it is a pursuit of individual success masquerading as a team sport. In no other team sport are personal statistics pored over so often and held with such reverence, or individual glory celebrated so vocally (see Sachin, various). While everyone says that they just love winning test matches and like doing well for the team, deep down every cricketer who's picked up a bat wants to put themselves in the history books. Sure, winning's nice, but what about a bit of personal glory?
Which makes Michael Clarke's decision to declare unbeaten on 329 slightly odd. Yes, as captain he should be seen to put the team first, but imagine the statue he would have got outside the SCG had he got past 400? In 9 months time there would be a boom of babies born in Australia, all nicknamed Pup, and he could have had his own ill-fated chat show. Against a tired, disinterested Indian attack, 401 and history was there for the taking, and Clarke let the pesky matter of trying to win a test match get in his way. And he didn't have the smarts to get a lucrative bat sponsor for this game. For shame.