For as incredible as Tim Duncan's career was in the NBA -- all 19 years and five NBA titles with San Antonio -- it speaks to his decades-spanning greatness that people still frequently recall and reflect on his four years at Wake Forest.

On the day of his retirement, let's do that once more.

Because Duncan signaled the last of an era, a rare player who was both undeniably special but also opted to stay in college for four years when he could've easily left and been a No. 1 draft pick after his sophomore or junior season. There have been other tremendous four-year college players in the 19 years since Duncan left Wake Forest, but No. 21 did it right as the high school-to-NBA fad was blooming and soon to dominate the league's draft cycle for the next decade.

Duncan was the last four-year star at a major conference to be taken No. 1 in the NBA Draft. (Kenyon Martin is the only player since to play four years of college and go No. 1, but he was not a national college star until the end of his junior season at best, whereas Duncan was in the conversation to be a No. 1 pick by the time he played 50 college games.)

Duncan was a two-time ACC Player of the Year and a three-time All-American. He swept all six major, national player-of-the-year honors in his senior season of 1996-97. He won back-to-back ACC titles with Wake in 1995 and 1996. Those league titles were the first the program won since the 1960s. Wake Forest reached the NCAA Tournament every season he was there; the Demon Deacons reached the Sweet 16 when Duncan was a sophomore and the Elite Eight when he was a junior. Duncan won 97 games while at Wake -- the most of any player in program history -- back when teams played 25 or 26 regular season games, not the 30 or 31 scheduled these days.

Here's a glimpse at some of his biggest moments wearing black and gold.

For his college career, Duncan averaged 16.5 points, 12.3 rebounds, 3.8 blocks, 2.3 assists and shot 58 percent. Those are amazing numbers, statistics that put him among the best college ballers ever. Duncan is the rare player whose college legacy blends seamlessly with his NBA one. He'll be forever known first and foremost as a humble, quiet five-time champion with the Spurs, but the Wake Forest run is very much a significant part of Duncan's story.

As Duncan grew older, his game became softer around the edges, more about feel and instinct than the raw, bony aggressiveness he played with at Wake. While in college, Duncan was at his most emotionally revealing and athletically wowing. He was spindly but not lanky. There probably haven't been five better defensive players at the college level than Duncan. He was a three-time national defensive player of the year, winning in 1995, 1996 and 1997.

Duncan in March 1997. He was a consensus pick for National Player of the Year. Getty Images

He's unquestionably a top-15 all-time player in the NBA, and looking at what he did for Wake Forest, you can make the same claim for his college career. He's the ACC's career leader in blocks, and he could make the case to be the best around both rims of any player in that conference's history. There have been 11 men's Division I players to collect more than 2,000 points and 1,500 rebounds. Duncan is one of them. This by a guy who reportedly only had offers from four schools: Wake Forest, Providence, Delaware and Hartford (!), and that came about in some part because Duncan picked up the sport at the age of 14. He originally was training to be an Olympic swimmer, but lost the pool he trained in to Hurricane Hugo.

So basketball became his hobby, then his sport, then his life.

The heyday of the ACC, for me, was the '90s. UNC and Duke were fantastic, sure, but you had Wake Forest, right there in North Carolina, becoming a national power thanks to Duncan and point guard Randolph Childress, who provided college basketball with one of the best guard-big man combos in the sport in the '90s. I'm hesitant to say we'll never have another player like Duncan come along, because who knows what the next 100 years will bring, but he did always feel like a timeless player with a personality from a far-gone era.

At first devastated, then ultimately and permanently inspired by the death of his mother when he was 14, Duncan came from St. Croix in the Virgin Islands to dominate the ACC, star in college basketball and then establish one of the distinguished runs in pro basketball history. To command at the college level for so long, then continue that mastery for almost two decades as a pro, it's something I hope we'll get a chance to see at least one more time in our lifetimes, but I wouldn't count on it. More than 20 years ago Duncan showed us why he was one-of-a-kind, even if he would never, and will not ever, say it.