Conversation so far:
what were happy days?
Happy Days is an American television sitcom.
what did Henry Winkler do on the show Happy Days?
Henry Winkler played the role of greaser Arthur Fonzie Fonzarelli, the breakout character of the 1970s American sitcom Happy Days.
did Henry Winkler get the part of Fonzie on Happy Days?
Henry Winkler played the role of greaser Arthur Fonzie Fonzarelli, the breakout character of the 1970s American sitcom Happy Days.
what was special about fonzie?
The Fonz was originally a secondary character, but was soon positioned as a lead character when he began surpassing the other characters in popularity.

Question: Are there any other interesting aspects?
Self-contained rewrite: Are there any other interesting aspects about Henry Winkler and Happy Days?