Even as a 13 y/o kid, I knew it a BIG deal.
As an aside, Hulu has an 8-episode mini series "11.22.63" It involves a HS teacher who goes back to 1961 and lives to eventually attempt to stop Oswald. Certainly an interesting concept and an entertaining series.
It was originally a novel by Stephen King. I’m NOT a fan of his but did like this one. The ending is a bit anti-climactic however.