Don't underestimate the desperation of the desperados.
Webber seeking his first win and first good start for what seems like years. Hamilton seeking to prove he is the ultimate street circuit driver after his mess at Monaco, plus seeking to get to his rightful place on the front row by the end of lap 1 to correct the Q3 fuelling error. Button wanting to finish the season as number 1 McLaren driver. Alonso expecting to fly past everyone at the start.
ps "youngest" is a misleading measure. It is only possible to win a WDC once a year, so I'd say Alonso, Hamilton and Vettel are equal at wining the WDC in the year of their 24 birthday. Of course that is all irrelevant, first you need your team to provide you with a good car.
Number of starts is important, but more importantly, he happens to have been on a young driver programme for the team with a dominant car.