Every now and then on his short walks from his South Loop condo to Wintrust Arena for DePaul games, Mark Aguirre hears the sounds of nearly four decades ago.

Fans call to him, pose for pictures with him, shake his hand, thank him for all the good times. It might as well be 1978 or ’79, and Aguirre might as well be superstar-strolling down Belden Avenue in Lincoln Park, two blessed hours on the court as the centerpiece of the can’t-miss Blue Demons beckoning him.

Man, it was good then. After leading Westinghouse to the 1978 Public League title — its first — as the consensus No. 1 high school player in the country, Aguirre hit college basketball like a tidal wave. DePaul reached the Final Four in his freshman season and was a No. 1 seed in the NCAA Tournament in his sophomore and junior campaigns.

Nobody was cooler than the Blue Demons. And nobody was better than Aguirre, who tasted defeat all of 10 times before leaving a year early for the NBA and becoming the top overall pick in the 1981 draft.

“It was such a magical time,” he said. “It was like we knew everybody in the city. Our team was embraced like the Bulls championship teams.”

Man, but it’s bad now. Aguirre is 58 and his alma mater, even with its swanky new arena, has all but fallen off the college basketball map. After a run of 13 NCAA Tournament appearances in 15 years, the last coming in 1992, DePaul has been back to the Big Dance twice — with a single victory to show for it — and not at all since 2004.

Sunday’s 82-77 defeat at Seton Hall dropped the Blue Demons to 10-16 overall and 3-11 in Big East play, which is painfully unremarkable given it’s their 11th consecutive losing season. DePaul’s Big East record over that period: an almost too-horrible-to-be-true 30-164. When your 11-year conference winning percentage (.155) is essentially the same as Jon Lester’s 2017 batting average (.148), something — make that everything — is amiss.

And here’s what the school’s greatest player ever has to say about it:

“If you’d have told me back when I was playing there that this would be the state of DePaul basketball, it would’ve been unconscionable. I would’ve said, ‘You’re out of your mind.’ Just think about it. Would you ever have guessed this? No. It’s unimaginable.”

How did we get from there to here? There are so many possible explanations. Ray Meyer couldn’t go on forever. The recruiting game got too big and too gnarly. Conference realignments washed away all of DePaul’s great rivalries. Playing in Rosemont, which the Blue Demons did for 37 years beginning with the 1980-81 season, was a joke. The right coach hasn’t been found, and the wrong people have been in charge of searching for him.

Again, possible explanations. And my words, not Aguirre’s.

“Everyone has their own opinions,” he said, “but I don’t think it’s right for me to make my opinions of that known. I’m not on the inside. I don’t know what they’re doing. I want to stress that I don’t know how it happened. It’s just hard to fathom that it did.”

Maybe you had to have lived through it to understand how visible and influential the Blue Demons used to be. They lit WGN on fire and were shown nationally on NBC as much as any school, anywhere. Remember the whole wristband-pushed-up-near-the-elbow thing popularized by Michael Jordan? Sure, you do, except that No. 23 wasn’t actually the one who introduced it to the masses.

It was No. 24 from DePaul, two-time first-team All-American Mark Aguirre.

“Do you know how many kids did that, from that point, all the way up to the NBA?” he said. “Jordan took it to another level, but that was all due to people watching DePaul. That’s a DePaul thing.”

Aguirre holds out hope that Blue Demons basketball will rise again. He offers little insight — positive or negative — about coach Dave Leitao or the higher-ups at the school, but he has been energized by Wintrust Arena.

“To be embraced by the city that you’re in is a huge thing, a very huge thing,” he said. “To go into a gym with big fans — real fans — as a player, it does something to you. You play different. You lift your hands and they get even louder. You build a relationship and a trust with the fans, and something magical happens there that helps you win.”

Aguirre laughed when it was pointed out that he’d just used “win” and “trust” in the same sentence.

“I’ll have to think about that the next time I walk there,” he said. “Maybe it’ll help them.”

Half a lifetime ago, he couldn’t have imagined they’d need it so badly.

Follow me on Twitter @SLGreenberg.

Email: sgreenberg@suntimes.com