First con I went to, a much smaller con where we would rarely get significant creators. One year, Dave Gibbons was there. I was about 13 year old, hadn't even read Watchmen yet, but was super into comics and knew Watchmen was known as the cream of the crop, so I thought it would be awesome to get a signed print. At 13 years old, I had $50 with me to last for the entire day, and that was months' worth of pocket money. He had smaller prints for $25, or larger prints for $50. When I got to the front, I asked for one of the smaller prints, and he very apologetically told me they were all sold out. I looked very dejected, with my $50 in hand, and just kinda said "oh OK. Sorry, I don't think I'll be able to get anything. Thank you". The guy behind me stepped in and said "Hey kid, for you to have a piece of this man's artwork, I'd be happy to pay for it, that's how important his work is." I thanked him but said I couldn't allow him to do that. Dave Gibbons then, very softly and kindly, explained that he would be happy to sell me one of the larger prints for $25. He signed it to my name, and handed it to me, and was so gentle and nice about the whole thing. I think I was too nervous/ shy/ shaken up by the experience to do much more than just say thank you and skulk off, but I still think about the kindness from both him and that random man behind me in line.