Mario's stories are told through his video games. Unfortunately some of the games can be twisted interpretations of what actually happened.
If you've played Super Mario Galaxy, you probably know the entire story arc of Mario going into space and being valiant and successful in his efforts to recruit the powerful cosmic goddess Rosalina and then vanquish evil King Bowser from destroying the entire universe.
That's all a fluke.
Mario did went on a mission to save Princess Peach from Bowser in space, but Mario miserably and embarrassingly failed to rescue Princess Peach. It's actually a pretty damning failure. In reality, for one mission to earn Power Stars, he was tasked to clean out garbage in Space Junk Galaxy under strict quotas for a Power Star, but the games trivialized it somewhat. The actual area Mario had to clean was much bigger and there were no explosives involved. Mario repeatedly could not get the Power Star he needed, and it took him so long to finally get the thing that Rosalina managed to find other Power Stars through exploration and whatnot, and she's the one who ultimately took on Bowser and defeated him.
Mario did manage to assist Rosalina through cleaning her clothes and arranging some books in the library in the meantime, but it was too late. Due to the single Grand Star he did collect (the rest were Rosalina's efforts), he was spared from the resulting explosion that Rosalina triggered to cleanse Bowser's influence. Mario, mortified of his failures, begged Rosalina to recreate a world where people thought he was savior of Peach from Bowser. His pleas worked, as he needed to maintain his positive image to help morale and security for the Mushroom Kingdomers and later on, he made up his adventures to the developers of Super Mario Galaxy so the video game was made to celebrate him.
Mario never got the Baby Luma (because it doesn't exist), so he never knew how to Star Spin. It was actually Rosalina's abilities. Rosalina was indeed missing her parents, however but the actual story about the Star Festival is exaggerated a bit.
Luigi wasn't even aware of these events. Not even before the world exploding.
Also Super Mario Galaxy 2 was also not an accurate recreation of events. It wasn't success or failure, however. Lubba does exist. Mario, however, spent this time cleaning the ship and doing basic maintenance that Lubba contracted him to do. The ship launched with success, and the game was made instead to celebrate yet another space-laden adventure. Everything, however, was made up.
The events of Luigi's Mansion are shockingly accurate.
The only thing about Paper Mario that has any bearing to the reality of Mushroom Kingdom is Mario's House.