I would say that his success lie on hard work and tremendous focus on the job. Also his quiet personal life helps too. But, on the race weekend he is the most focused and success driven F1 driver right now.
yip
when Bridgestone withdrew from F1, Japan's Fuji TV made and run Bridgestone tribute program which mainly consisted of close covering of Bridgestone activities at venue and Hamashima in 2010. In that program was often captured that Vettel haunted Hamashima to ask about tyre - him waiting or visiting motorhome for Hamashima, calling mobile to Hamashima etc.
And asked about what he think about 2010 championship result right after Abu Dhabi flag, Hamashima said sth like "it's not bad to see a driver who came so passionately to ask us about tyre winning the WDC".
Of course you can be cynical to guess TV producer picked and highlighted Vettel part intentionally coz he was WDC, and of course Alonso, Massa Lewis etc must be no less serious about tyre. But in various media outlets and interviews (mainly in Japanese), Hamashima often mentioned about Vettel attitude and anecdotes of Vettel coming to ask him about tyre often, discuss about tyre with bs engineers alot, and give phone call to Hamashima often.
I knew and was following that back then so this recent pic looks lovely and tells alot to me
this Hamashina/bridgeston/2010 story alone can give some clue to how much hard work he must be actually doing behind the scene that might be overlooked by quite a few people.