Likely to be an old friend, or a stranger?

There’s this guy who said we might know each other; and he knew stuff about my interests that I hadn’t shared online. He said (after we’d had a chat); that he really likes me.

Is there an implication there that we do know each other in real life? Or is it likely to be a pickup line? I don’t have any pictures of myself online. I do already know two people who were on this site. So I like to keep things private.

Likely to be an old friend, or a stranger?
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