(Jump to 1m57s.)
Used to indicate how tough things were when the speaker was a kid, acknowledging that there might just be some humorous exaggeration for effect. Also used in response to a speaker who's ranting about that topic, as a curt dismissal: "Yeah, yeah, we know. Uphill. Both ways."
More than the moon landing, more than the Nixon resignation -- this was the defining moment of my generation. Every Baby Boomer and the early batch of Generation X has heard this routine, and knows this phrase, even if they can't place the source.
And yes, heard it, not "seen" it: back in those days, we didn't have your YouTubes or your DVDs or your Comedy Centrals. We had to get our comedy on LPs -- big, black hunks of vinyl with sound physically etched into it that you had to play back with a needle, a real, physical needle, not a beam of light.
Analog. None of this fancy "digital MP3" mumbo jumbo.
If we couldn't get our hands on a comedy LP, we might make scratchy, bootleg tape recordings off the radio -- if we were lucky enough to have an FM station that carried The Doctor Demento Shows for a couple of hours, once a week.
Most of us just had AM radios that played disco and elevator music.
And we were thankful for them!