It really depends on what relic it is that I find. I have a wallet that used to belong to my dad, and since he died when I was a baby, it usually makes me feel kind of sad.
I love finding old stuffed animals or gifts people gave me because I can go back and have the memory of the time and person. I have a huge four foot tall pink flamingo my Granpa brought me when I was about five. Last time I talked to him we were talking about the day he brought it to me. He walked off the plane carrying this massive flamingo, and my whole face completely lit up. It was so great. I love it.
I still have an old shirt my grandmother knitted for me. I found it in an old box in the attic while I was pulling down the Christmas tree. That brought back memories of playing in the snow in Germany with my grandparents. I haven't seen them since I was 6.