Sometimes coaches lead fans to believe (largely because they let them) that they are part of their family, and will stay forever and ever.

All one has to do is say, "This is where I always want to be," and the fans will hear it as, "I will never leave."

As Brad Stevens is introduced today as the new head coach of the Boston Celtics, not everyone is focused on his arrival to the NBA as much as his departure from the college ranks.

This is the guy who made it seem he would never jilt little Butler, turning down UCLA and all kinds of other big-time opportunities. And we’re told the Celtics are not the first pro team to court the 36-year-old miracle worker who directed the Bulldogs to back-to-back Final Fours.

In 2010, after pushing Duke to the limit in the NCAA championship game, Stevens received a 12-year contract.

His departure is evidence that you should be very wary about long-term deals and what they really mean. They don’t lock up great coaches as much as they put a potential strain on the colleges rendering them — especially if they’re not negotiated and written properly, and the coach turns out to have happy feet or be less than great.

CASE IN POINT of the latter: the University of Hawaii being saddled for more than a million dollars a year for football coach Greg McMackin with no buyout provisions, guaranteed money for five years.

You may recall this bad deal was the result of a successful predecessor — one who had his constituents believing he’d never leave — digging out for Dallas and SMU in early 2008. McMackin got the money June Jones was supposed to get.

To this day there are people who swear they heard Jones say he’d never leave Hawaii. I don’t recall that. What I remember is him saying he loved Hawaii, and UH was his dream job.

There are a lot of differences between Stevens and Jones, but there is at least one similarity. They led people to think they’d stay forever, intentionally or not. But you have to be naive to think there is anything close to forever in sports.

As it is with successful coaches it is in the world’s most impossible karaoke song, "Sara": No time is a good time for goodbyes.

Some are better than others, but Jones’ departure after the Sugar Bowl debacle and Stevens’ with a small replacement pool available were equally bad timing for different reasons.

The problem is no one can choose when the right opportunity comes. The SMU Mustangs might wait a little while for you but the Boston Celtics certainly won’t.

THE BUTLER administration seems less stunned than the rest of the basketball world about Stevens leaving, and has moved quickly to interview a couple of potential replacements.

Butler basketball minus Stevens could suffer a downturn like UH football did. It must be very careful with this next hire. Go interim for a year if you’re not sure.

Those who say Stevens did the Bulldogs wrong are silly. He made Butler a legitimate college basketball power and a member of a power conference. They’re Duke, Jr., but now minus their Coach K.

Where would UH football be if Jones hadn’t left? Maybe the better question is the same one to ask about Stevens: What would the program had achieved if he’d never arrived?

Reach Dave Reardon at dreardon@staradvertiser.com or 529-4783 or on Twitter as @dave_reardon.