In 2018, Danica Patrick told Joe Rogan that she made the decision to retire from motorsports as many different factors had pointed her in the direction of stepping away during the 2017 season. The American explained that she had made peace with the decision and also had other things she wanted to do outside of racing.
Danica Patrick decided to retire from motorsports and last competed in the 2018 editions of the Daytona 500 and Indy 500. This was like a farewell tour, which she called the 'Danica double', as she aimed to pay homage to the two series she raced in, NASCAR and IndyCar.
Speaking on the Joe Rogan Experience podcast in January 2018, the former IndyCar and NASCAR driver was asked by Rogan why she decided to call quits on her career. Patrick replied saying that had made her peace with the decision. [1:00 onwards]
"I'm ready. I mean, I love racing, but I love other things too. So, you know, I'm okay with transitioning out," said Patrick.
"And there were a lot of things that were pointing me in this direction, in 2017, stuff that has never happened to me before, to kind of head towards the exit a little bit."
Danica Patrick then went on to explain that one of the things that happened in 2017 was her primary sponsor left her at the end of the season.
This sponsor was Nature's Bakery, who had sponsored Patrick for the 2017 season. The American subsequently lost her seat at Stewart-Haas Racing for 2018, mainly due to not having a primary sponsor, and then decided to call it quits on her motorsports career.
Danica Patrick explained how the idea for the 'Danica double' came about

Speaking during the aforementioned podcast appearance in 2018, Danica Patrick explained that it was her agent who suggested finishing her career at the Daytona 500, and she subsequently asked about ending her career at the Indy 500. She also explained that doing both the historic events felt like the 'right way to go out'.
Speaking on the aforementioned podcast, Patrick mentioned that she told her agent to 'be ready for me to be done', before he suggested an idea to her:
"So then he came up with the [idea], 'what if you finish up at Daytona?', and I was like, 'what about the Indy 500?'. And I was only really referring to the Indy 500, and he was like, 'I'd love you to do both.', and I was like, 'oh, that's a good idea'."
The 'Danica double' did not pan out as she would have hoped for though, as Patrick did not finish either race, crashing out in both the historic events. She got caught in a multi-car crash on lap 102 during the Daytona 500, whereas she lost control and crashed into the wall on lap 68 of the Indy 500.