As time went on, and the months and years came and went, he was never without friends. […] But Charlotte's children and grandchildren and great grandchildren, year after year, lived in the doorway. (22.67)
For Wilbur, his friendships with spiders seem to have no end. Instead of stopping when the spiders die, he gets new friends every single year. This means he's always making new chums, which is cool. But it also means he's always saying good-bye to old friends, and that's got to be tough.