Oops, I forgot the WHY parts.
If I was to pick a man it would be Jesus, because my faith is still weaker than I wish it was, and I could think of nothing that would bolster it more. Honorary mention would be my father, because I have no memories of him.
If I was to pick a woman, hmmm, Kerri Green back when she was 17, and make me 17 again as well. Mainly because I had a massive crush on her back when I was younger. (Kerri Green is the girl from Lucas, The Goonies, and Summer Rental).