We all know that Carmelo Anthony is adamant that he won't come off the bench in the NBA. In his career to date, he's started every game he's played in: 1054 regular season games and 72 Playoff games, for a total of 1126 out of 1126. When it comes to All-Star Games, he's eight for ten in that category, but he's obviously had less control over that. When it comes to games that count towards the season standings and overall results, he's started them all.
Diving into it a little deeper, I fired up Basketball Reference, and confirmed that Carmelo Anthony is the only player to have played in at least 1054 regular season games and started them all. Others are very close. LeBron James came off the bench once, Gary Payton twice, and Tim Duncan thrice. Melo stands alone however, with the most games played while starting every one. In fact, he's the only player to have played 1000 games or more and started every single one. Extending back to a minimum of 1000 games, Dwight Howard also joins the list of at least 1000 games played and started, but he also came off the bench once. It's a less impressive streak and total when it comes to Melo's Playoff games, but the fact remains that he's started every regular season and Playoff game he's appeared in.
That's something a lot of Hall of Famers and future Hall of Famers cannot say, and while there are still candidates to join him - Kevin Durant has started all 771 of his regular season games, and all 127 of his Playoff games - for now he's the only one to achieve that while playing in at least 1000 regular season games and counting. Obviously we can only speculate as to his thoughts and awareness of the specifics, and players of Melo's stature tend to prefer starting to coming off the bench anyway, but it's not unfathomable that he'd like to go down in history as starting every game he played in; perhaps the only player to do so (at least for many years), the first player to retire with that statistical distinction, the first player to reach 1000 games doing so, or whatever. He may not win a ring, he may not hold any other league records of note, but he has a shot at this one. Beyond his ego not liking the idea of coming off the bench, he could be well aware that he has a chance to hold some distinction, some record, some trivia note that a lot of the all-time greats cannot boast.
If nothing else, I think it's interesting to note that he is the first and so far only player to play in at least 1000 regular season games and start them all, and start every Playoff game as well; officially at least, since Games Started wasn't tracked until 1982. It's also interesting to compare that to other players who came close, or you'd think would be closer. As I noted, Kevin Durant is still eligible, while LeBron James isn't due to one game coming off the bench. Gary Payton, Shaquille O'Neal, Tim Duncan, and Dwight Howard are all within ten starts of the mark. Russell Westbrook is out, owing to 15 games he didn't start during his rookie campaign. Stephen Curry and Klay Thompson are already unable to match the feat, as are Giannis Antetokounmpo, James Harden (notably a former Sixth Man of the Year), and Anthony Davis. Players like Joel Embiid, Ben Simmons, and Jayson Tatum are in the running, but obviously have a long way to go; Donovan Mitchell has no shot at it, coming off the bench in eight games in his rookie season. Other eligible players with a bit more experience include Kyrie Irving, Damian Lillard, and Karl-Anthony Towns. In fact, Towns is off to a strong start, having also played and started in all 82 games each of his first three seasons.
For now they're still chasing Melo, and as long as he's not willing to come off the bench - and no one makes him do so - the distinction is his. If nothing else, considering all the other big names who commanded starting roles throughout the years, I think it's interesting to note that he's got the record, and the chance to be the first player to retire with that distinction.