Admitting wrong-doing is a good way to begin to absolve yourself of any wrongs you may or may not have committed, and considering that there's still a contingent of Chelsea fans (not unreasonably) upset at Samuel Eto'o for comments he made in 2005, the fact that he's admitted being a little bit silly is probably worth pointing out:
I must say that when I first met Mourinho, I never thought I was going to work with him. I got it wrong and if I am not mistaken, I believe I said that publicly.
NB: Eto'o also had some choice things to say about the club itself, but I think everyone's understanding is that it was mostly an attack on a team that Jose Mourinho happened to be managing rather than on Chelsea.
Everybody has an opinion on José without actually knowing him. I say thanks once again to God for giving me a season with him at Inter. We both understand that we were born to win together, so it is a good thing.
It's not quite an apology, but admitting that he was wrong to have been so angry about Mourinho and Chelsea in the past -- notice how he's not trying to defend his actions at all -- is probably enough for most to forgive and forget. Frankly, I'd guess that before the old quotes were dredged up, almost all of us were on 'forget' mode.
Eight years ago, Samuel Eto'o said some dumb things about Chelsea Football Club. Eight years ago, Samuel Eto'o, by his own admission, didn't know what he was talking about. Happily, the intervening time has seen that error corrected.