Disclaimer: Harry Potter, Hogwarts, Neville Longbottom, and the magic of this world are the sole creation of the phenomenal J. K. Rowling. I do not own these characters. I am merely borrowing them.
When he finally stood up to someone it was to Harry, Hermione and Ron. For his courage, he was hexed.
When he told Harry about Magical Mediterranean Water-Plants and Their Properties, he felt pride that he was finally good at something. Too bad Harry didn't appreciate it.
When he covered everyone in Stinksap, he was completely mortified. He'd never impress his friends this way; Harry didn't even want to be seen with him.
When he told Harry that they were coming with him, he simply wanted to help him. He earned Harry's respect that day.
When he heard Harry defend him on the train, he finally knew it. Neville Longbottom did, indeed, belong in Gryffindor.