An exaggeration is one thing. Misremembering is another. A lie is a third, different thing.
Ryan misremembered the facts about something unimportant that happened in the last millenium - and he has since corrected himself.
Kerry, Obama, Clinton, Sharpton (etc, etc) lie. And lie. And lie.
Misremembering is one thing.
An exaggeration is a lie dressed up in its Sunday best.