The Revelation can be a powerful moment in a character's life. They learn something that overthrows everything they (thought they) knew about themself and the world around them.
No reason not to make it a joyous occasion!
Obi-Wan: Your name is Luke. Luke Amidala.
Luke: Whoa, this is definitely better than binoculars.
Obi-Wan: I was there when your mother named you. Your real mother.
C-3PO: We were all there at your birth.
Luke: Whoa. That's not true. That's impossible!
Luke: It says right here on my character sheet, "Adam Lars".
Obi-Wan: Owen and Beru are your uncle and aunt. They've devoted their lives to your protection.
Luke: My protection?
Obi-Wan: You're a Jedi, Luke.
R2-D2: Congratulations. Your life expectancy just went from "senile pensioner with a space-bus card" to "missing your next birthday".
R2-D2: Which, by the way, is actually tomorrow.
C-3PO: Happy Birthday!