Why is Killoggs black today?

1. Those I have learned from Missy Elliot videos
2. Moving to San Francisco from Los Angeles
3. Getting into Killoggs
4. (I'd reveal move #4 to the GC if there still was a GC)

I've come across this problem in the work environment that I'm not sure how to handle so I thought maybe you guys could help. I've been at it in tourism sales for about 7 years, worked in tourism since college, and I just had a birthday that put me just under 31.
The problem I'm having is when I encounter business associates over 45 years old who in conversation say "I could have a child your age" or "You were probably just a baby when I did such and such" or "You probably don't know about that because you weren't born yet".
Just yesterday I was at lunch with 3 people who were all over 45 and this part of the conversation lasted way longer than I would've liked it to. Another time I was out after a convention with a bunch of people at a bar and when I played Creedence Clearwater on the juke box somebody said " What's this! Did your daddy tell you about that song?" and everybody laughed.
I am tired of this kind of humor and don't see what the point is. I am flattered to be young but the impression they give me is that because I'm young I'm stupid and don't know anything about anything. The only thing I can do is not laugh and change the subject but I could use some clever responses to these stupid remarks.