Brad Keselowski looked back at the time he drove for Dale Earnhardt Jr.‘s JR Motorsports in the early stages of his NASCAR career. On Kevin Harvick’s Happy Hour podcast, the 40-year-old driver talked to Harvick about something special Earnhardt said to him. “His plate was really full and he was really stressed,” Keselowski said about Earnhardt. “At one time, he said to me something I’m so proud of, I’m thankful he kind of had the courage or the guts to say it. …But he was like, ‘Man, that was one of the toughest times in my life. I had all the things going on in the Cup side, and the Xfinity t…