When I was around 8 I was riding a honda 50cc at my cousins ranch. I stopped outside the house and saw a perfectly white spider on my knee. I was wearing shorts and it started crawling up my thigh. I brushed vigorously with both hands to try and get it off but my hands passed right through it. It crawled up my shorts and disappeared. I jumped around for a minute smacking where I thought it had gone but there was no trace. That's something that always stuck with me.