"Our imperfections make us unique as surely as our strengths." - Toni Sorenson
The first thing he heard about his parents growing up was how great they were. How great of a wizard his father was. How kind his mother was to everyone she met. Their bravery, nobility, and other good traits were spoken of so often that he could guess the words out of a stranger's mouth before they spoke.
Neville never heard of how Frank Longbottom had a rotten temper. Or the way Alice Longbottom got envious over Lily Evans' grades and Frank got jealous over the way professors loved Sirius Black, who never put as much effort into his work as he did. Frank was one of the most stubborn individuals to walk through Hogwarts while Alice's clumsiness could only be rivaled by Nymphadora Tonks' decades later. These faults were never mentioned, not once. Over time people forget they existed and in their wake laid the almost impossible perfectness Frank and Alice seemed to be.
Neville was proud to hear about how great his parents were. But knowing only of their bravery, nobility, and their endless other perfect traits made their personalities almost… unreal. They didn't seem to have the simple flaws everyone had. The stories of Frank and Alice Longbottom made them ghosts of their true selves and Neville never truly knew their little kinks that made them human.