I get the same thing, even more so than that. Sometimes I'll be sitting watching TV, and someone will be in the kitchen (just outside of my peripheral vision), and suddenly someone will be sitting next to me, and I still think someone is in the kitchen cooking, but whoever just sat next to me was the one in the kitchen. Even when I understand I'm just high and I won't let it happen again, it happens. I like when my mind plays tricks on me like that, as long as it's in good fun.