Have I written this before?

If I haven’t … I should have.

Thank you, Jose Canseco. Thank you for telling us what we didn’t want to hear about baseball and steroids. Thank you for never giving in, never going into a shell when fellow users were calling you names, like “delusional” … and said you had a “personal agenda.”

It’s not often that a guy so universally scorned can sit back and — over and over and over again –  say “I told you so.”

Now, let’s stipulate Jose Canseco is no hero. If we also believe his claims about his own use of steroids, he practically pioneered the abuse of performance-enhancing drugs in the game of baseball. For that, he deserves eternal censure … until we realize if it hadn’t been Jose, it would have been someone else.

And all those guys looking for an edge, from Mark McGwire to Rafael Palmeiro to Alex Rodriguez and Jason Giambi … do we really believe they would never have touched the stuff, without Evil Jose showing them how?

What we need to remember about Jose Canseco is this: He is approaching a 100 percent score on accusations leading to confessions or suspensions.

Canseco wrote in his book, “Juiced,” back in 2005, that McGwire used PEDs, that Giambi did, that Palmeiro did. He later said he was confident that A-Rod did.

And he has yet to be proven wrong. Not once.

Let’s see what an indignant McGwire said about Canseco, in a statement to “60 Minutes,” back in 2005: “Once and for all, I did not use steroids nor any illegal substance. I feel sorry to see someone turn to such drastic measures to accomplish a personal agenda at the expense of so many. The relationship that these allegations portray couldn’t be further from the truth. Most concerning to me is the negative effect that sensationalizing steroids will have on impressionable youngsters who dream of one day becoming professional athletes.”

Uh, yeah. That would be the same Mark McGwire who made the tearful confession on Monday.

The same McGwire who Canseco says still isn’t telling the truth, attempting to peg the start of his steroid use to 1994 instead of the late 1980s — which is when Canseco said he and McGwire used to shoot up together, in their Oakland Bash Brothers days.

For that same Canseco interview, “60 Minutes” read a statement from Palmeiro’s lawyer that said, “Mr. Palmeiro categorically denies that he has ever engaged in illicit use of steroids or any substance banned by Major League Baseball.”

Ha. Ha-ha.

And Giambi? Just before the February 2005 interview, he said of Canseco to reporters,  “I think it’s sad. I think it’s delusional.”

Excuse me, I think I’m about to sneeze … ah, ah, AH … b&llsh*t!!”

Jose Canseco is not a good guy. He was one of the players who ushered in baseball’s Steroid Era, when the game’s hallowed numbers were warped out of recognition by laboratory freaks like McGwire, Sosa and Bonds.

But, again: Canseco hasn’t once been proven wrong in his naming of names. Not once.

He may be a bad man, and he may be a snitch, but for the past decade, when it comes to ‘roids and ballplayers, Jose Canseco is the truth, the whole truth and nothing but the truth.

We owe him for making us confront reality, and deal with it.