"I had a problem with the fuel pressure as soon as I went out, there was alarms for my fuel pressure," he revealed. "When the race started, when I pushed the throttle, I had a big cutoff. When I changed gears again, it was people going bang, bang, bang. I was dealing with that the whole race."
Barrichello also found the starts challenging and unlike anything he'd experienced. After a three-wide start to the race, the restarts were meant to be single-file - but more often than not broke out into a multi-wide free-for-all instead.
"The first start, I had really to be careful," said Barrichello. "I saw people trying here and there. I also tried on the outside.
"But the restart, so many other occasions, it depended who was leading. They started in a different way. I was in between like P5 and P15 all the time. I started accelerating in different areas. That's the question. By the time we got to the line, it was four-abreast. That for me was more impressive than the actual start of the race!"
So was that it for Rubens and oval racing at Indianapolis? Not a bit of it. Like almost every racer who has dabbled with an Indy 500, it has proved an instant addiction.
"I'll be back!" he insisted. "In my life, whatever I do, whatever is right or wrong, I have fun. I have fun. If I am sitting on this car, it's because I'm having fun. I've already proved to many people that I could have quitted. I have a wonderful wife and kids. I could stay home in Brazil. But I still love this too much. I honestly do this because I was made to do this."
But after the heights of the Indy 500, it's back to the "day job" and life as an IZOD IndyCar Series regular - with normal service resumed as early as this upcoming weekend. He was hoping to take some of the lessons from Indianapolis forward with him into the rest of the 2012 season.
"I tell you, I think that my experience here on the oval will help me have at least more feedback from the cars. You run on such a light downforce that I think it will help me," he said. "I look forward for Detroit next week. Actually, I'm testing Milwaukee on Tuesday. It's everything happening so fast. But I'm a pretty fast learner, as well, and I'm enjoying my time."
And having experienced and mastered the basics of oval racing, he's now determined to master the advanced skills as well and learn how to move off that inside line when he needs to.
"By next May I will try outside, outside, outside!" he said. Sounds like fun - and should be a sight to see.