I have a lot of respect for Andrew Luck, the Indianapolis Colts quarterback who abruptly retired this weekend.

I have a lot less respect for the literal armchair quarterbacks who are criticizing his decision. 

A former number-1 draft pick, Luck's pro career highlights include just four playoff seasons (his best year was 2014, when his team made it to the conference final but lost). He's probably not destined for the Hall of Fame with that record.

But he's also gone through major injuries, and at at age 29, he's newly married. His wife is pregnant with their first child.

And he just no longer has the fire in his belly to compete in the NFL.

Unfortunately for Luck, a reporter broke the news of his decision to quit in the prime of his career during the Colts preseason game Saturday, and fans booed the former starting QB. He said afterward that hurt, since it's likely the fans' last goodbye.

And they weren't alone in putting him down. Fans, including people who chose him in their fantasy football drafts, went off on him a bit. (Among them, of all people: O.J. Simpson. No, I'm not going to link to him.)

Predictably, some media types used Luck's decision as a reason to bash his entire generation. ("Retiring cause rehabbing is "too hard" is the most millennial thing ever").

But all of that is just stupid. If you're reading this, you're almost certainly either a business owner, or an aspiring entrepreneur. That means you know a few things about success.

One of them is that it's almost impossible to achieve anything if you don't really want to achieve it. 

That's exactly how Luck described his decision: "I know that I am unable to pour my heart and soul into this position."

Professional football is a very dangerous sport. Setting aside Tom Brady, who seems superhuman, we've seen time after time as players retire early, often because they see what happens physically and mentally to some who stay too long.

The most extreme example among them might well have been one player who literally retired during a game last year.

Luck is giving up at least $58 million in guaranteed money to quit now -- and the owner of the Colts estimates he might even have earned another $500 million, if you were to add up all of his potential future contracts as a player.

But what is that worth anyway? Is it worth his health?

Besides, he's earned a total of $97.1 million in his career, and it's not as if he's unlikely to continue earning. It's also possible he could un-retire, much as Michael Jordan (NBA), Tiger Woods (golf), Mario Lemieux (NHL), and George Forman (boxing) did.

I wrote recently about a study that suggests 87 percent of people with at least $1 million in liquid, investable assets, consider themselves wealthy. For some people the money can never be enough.

Kudos to Luck for knowing when it's time to quit -- and making the decision no matter what the backlash might be. When your hear is no longer in whatever you're doing, it's time to find something else.