Legacy was, as legend tells it, a Phoenix who had saved Equestria, and other countries, multiple times throughout in his life.
The friends he had gained through his journey to bring peace to all nations had all been through one thing or another that brought them to strive for the same goal. Legacy had never thought much on it after they had given him their story, but when you tell a story, you don't usually tell it in exact detail.
These ponies, gryphons, birds, and virtual intelligences all had a journey before Legacy. When they tell the tale, it flashes through their mind in a split-second. But if they told you the whole story...