How many times do you think someone has walked into the Petco to see the snakes and then after seeing them turns around and walks out? Maybe the manager asked you about your intentions to buy a snake because she didn't want to bother the snakes again. Maybe the snakes had been bothered all day long by curious people and she didn't want to stress them out anymore. Maybe the kid you talked to has a vast knowledge of fish, cats or dogs. You were just another customer that had a question at the time. You have no clue what happened in the hours before you arrived at the store.
I used to work at a local owned pet store 20 years ago and I couldn't stand snakes at the time. I wouldn't pick them up at all because I was scared of them. But if people had a question about cichlids or saltwater fish, live rock or corals I was the go to guy. That is why I was there. If someone had a reptile question I knew who to send them to because he knew reptiles. We also had people that knew about all animals in the store. That's just how it all worked out. I got into the reptile side because I liked lizards and wanted to know about them. I eventually got into snakes because I had a fear of them and wanted to overcome it. I am now very glad I did because I find them very interesting and I currently study whatever I can about the species. Getting into the breeding side and studying the genetics are the next step for me. I grew into snakes, they weren't my first choice but I think they were a great choice as I look back.