Even as he hits the big four-oh today, Rubens Barrichello continues to approach racing – and his first Indianapolis 500 this weekend – with the fresh-faced enthusiasm of a rookie. Surely that's a key part of his ability to maintain a world-class open-wheel racing career for two decades.

Barrichello spent 19 seasons in Formula 1 between 1993 and 2011. After losing his seat at the Williams F1 team, Barrichello switched to the IZOD IndyCar Series this year with the KV Racing Technology team, and already is establishing himself as a fan favorite. IndyCar reports that the recent race in Sao Paulo had nearly 10 percent of all households in Brazil tuning in to watch, and Barrichello was no doubt the reason why.

Both his father and paternal grandfather are also named Rubens, and Barrichello shares his father's birthday. This was how he earned the nickname "Rubinho," which is Portuguese for "little Rubens."

Barrichello got his racing start in karts in his native Brazil, winning five titles before moving to Europe to race in the Formula Vauxhall Lotus series in 1990. In his first year, he won the championship, a feat he replicated the following year in British Formula 3, beating David Coulthard. After finishing third in Formula 3000 – the stepping-stone series to F1 which now goes by the name of GP2 – in 1992, he joined the Jordan F1 team for 1993 (ABOVE).

After long stints with Ferrari, Honda, Brawn and Williams, Barrichello has scored the eighth highest points total in Formula 1 history. Barrichello drove for Ferrari from 2000 to 2005, as Michael Schumacher's teammate, enjoying considerable success including finishing as championship runner-up in 2002 and '04.

Barrichello became the first driver to reach 300 grand prix 300 starts in 2010. This month, though he's just a rookie again at the Indianapolis 500, and by all appearances loving every minute of it.