Jeff Burton didn’t hold back when it came to his thoughts on Martin Truex Jr. retiring from NASCAR. While talking to Nate Ryan of NBC Sports, the former NASCAR driver and current analyst explained why Truex announced his retirement this year. “I just don’t think the casual fan can understand how grueling of a lifestyle it is,” Burton began. ” Look, it’s not without reward. It’s not a pity party here. It’s not without reward, it’s not without good pay, it’s not without a lot of things that a lot of people would just be very envious of. But it is a massive sacrifice. “…My wife knew she came seco…