Matthew McConaughey -- 'I Was Pissed Off' at Lance Armstrong

Count Matthew McConaughey among those who were upset to learn Lance Armstrong had been lying all these years about doping ... saying he was mad at his close friend, but then eventually felt sad for him.

McConaughey and Armstrong have been BFFs for years -- both call Austin, TX home and the two have been known to work out together often.

But McConaughey says he was as surprised as anyone when Lance came clean, saying he took the news personally at first, but realized it was wrong to do so.

He told MTV News, "What was he supposed to do? Call me to the side and go, 'Hey man, I did it but don't tell anybody.' Then I would have really had a reason to be pissed off at him, going, 'You want me to walk around holding this?'"