You had hairs on your arms when you were ticklish? Over time, they became more, because the tickling accelerates the growth of hair on the hands.
Answer from: Mikhail Starovoit:
Michael and Olga, blogging about sex toys, sex shops and something about sex...
No) I don't understand any connection between tickling and hair growth at all. Well, what more do they need for me to post my answer?