Get real, Jim, it's totally obvious what "Blowin' In The Wind" is about. It's a broad-ranging philosophical comment on mankind's still unsuccessful struggle to achieve things like social maturity, equality, justice, brotherhood, and peace. Dylan probably wouldn't have written it were he not so inspired as a young man by the example of Woody Guthrie's championing of various social causes in song, but it fit perfectly into the revolutionary spirit of the time (in North America in the early 60s) and that's why it made such an impression on people then. I won't trouble you with explaining it any further than that, because if you don't get what it means by now, no further explanation would help, in my opinion. ;-)

john f - I believe you have just hit on what may be the key problem with "I Started a Joke".