When you buy bananas, you know that you have eat them within a certain timeframe or they go bad.

That’s the deal: enjoy them while you can.

You don’t buy them and say, “Well, these are going to spoil soon, so I better get rid of these now and go back to the store and buy another bunch.”

Some Patriots fans owe Tom Brady an apology.

These fans will firmly and loudly proclaim that Brady is the best quarterback to ever live.

They’ll just as firmly declare that Brady is still the best quarterback in the game right now, and don’t you dare say anything about Aaron Rodgers.

These same fans, though, have wondered aloud if it’s time for Brady to leave in order for the Patriots to keep Jimmy Garoppolo around. The worry is that the 39-year-old Brady’s career is almost over, and these fans don’t want to lose his successor.

I realize that most Patriots fans recognize the folly in this. But, since New England won Super Bowl LI last month, I’ve heard it more than I should.

First, let’s examine what Brady has done for the Patriots.

He’s led them to five Super Bowls and seven Super Bowl appearances. They’ve been not only playoff contenders, but championship contenders just about every season since 2001.

In his most recent game, he led the Patriots back from a 28-3 deficit to beat the Atlanta Falcons in the Super Bowl.

Brady will be 40 when next season starts, but he’s still playing as well as any quarterback in the NFL.

Now, let’s examine what Garoppolo has done for the Patriots.

Uh … Nothing, really. His crowning achievement has been those early-season wins over the Cardinals and Dolphins.

Garoppolo has flashed potential, no doubt. But Brady can flash an entire handful of Super Bowl rings.

I’ve experienced all this before. Remember when Peyton Manning sat out the 2011 season with an injury? I was living in Indianapolis at the time. When it became clear how bad the Colts were going to be, many suddenly decided it was time for Manning to leave so the team could draft Andrew Luck, or possibly Robert Griffin III, with the No. 1 pick.

That situation was a little bit different than the one in New England right now. There were legitimate concerns that Manning was physically unable to play.

But the idea was the same: start the next era now.

Look how that turned out. Manning went to the Denver Broncos. He wasn’t the same, but he still took the team to a pair of Super Bowls, one of which they one.

Indianapolis drafted Luck, and he’s been really good. But he hasn’t been Manning-good, nor have the Colts.

Can Garoppolo be better than Luck? Sure, but it’s not likely. Quarterbacks as good as Luck are rare, and he’s not even among the best of the best in the league right now. Tom Brady is.

Look, I get that it’s important to look ahead and plan for the future. But don’t buy the future at the cost of the present.

With Brady and Belichick, Patriots have a great thing going. Maybe the greatest 15-year run in NFL history — probably in the Super Bowl era. And there is no reason to suggest that the run is over. Brady’s about to be over the hill, and on the other side he might find another Lombardi or two, or three.

It might not seem like it to football fans in New England, but Super Bowls are hard to win. Even the great Tom Brady went an entire decade between his third and fourth Super Bowl wins.

Garoppolo might develop into a tremendous quarterback. But the odds are slim that he’ll ever be as good as Brady is right now.

Don’t put the security of the next decade ahead of what could be a few more years of Brady brilliance.