New England Patriots' former tight end Rob Gronkowski shocked a lot of people after the Super Bowl last season when he retired from the NFL abruptly.

Gronkowski had kind of hinted at retirement for years in the past. However, he was just 29 when he announced it and on top of his game. He was one of the best players on a dominant Super Bowl winning team last year.

It's starting to make more and more sense though. Yes, everyone knew he had injury and concussion problems. Now the issues are coming to light even more though.

That's a lot of serious concussions. Rob Gronkowski isn't using his concussions as something to attack the NFL with though. He wants to use those concussions as a way to teach his kids about the dangers of football, while also giving them the choice to play if they want.

We all know the injuries. Adding to it that whole “pint of blood” business that was mentioned in this tweet, and you understand why he retired. Then add the concussions and you suddenly don't know why he didn't retire sooner.

It should be noted though, Gronkowski made it known that he is “fixed.” It sounds like he wants people to know he's healthy now. Could that be for a comeback? Or just to let people know he's doing alright?

Gronkowski will go down as one of the best and most dominant tight ends of all time. It's incredible to think about because he was only 29 when he retired. He could've easily had another five-plus years of dominance in his future.

However, it's pretty clear that those years would've done irreparable damage to the man himself. Hopefully, Gronkowski can stay healthy and enjoy whatever crazy endeavors he wants to get into. I'm sure that is all fans of the Patriots want from him too.