Guy's Behavior

What do you think this guy meant when he told me this?

This supervisor of mine went up to me and told me, “you’re quick to judge, you make generalizations, and you’ll probably be wrong.”
Was he calling me a jerk or possibly even possibly a pretty terrible person? Or did he mean it a little less harshly? Maybe the answer should seem obvious but it doesn’t feel that way right now. I’m not completely sure and it seems like people can sometimes interpret things differently. Is it possible he didn’t mean it as badly as it sounded to me? Also, what confused me was that he would otherwise talk to me at work and it tended to be in a friendly way even in spite of what he told me, and he sometimes would even chat with me. What was his intention? I have some idea but I thought I’d get another person’s perspective.
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I’ve already explained what happened, but I’ll give context on this. I didn’t say anything to him first, he simply came to me and told me the above.
I don’t remember if this was in the days before or after I said something to a co-worker that was inappropriate but not necessarily meant personally (though it was said poorly and it might have interpreted that way). It wasn’t at the same time I said this to my co-worker but I wonder if it might have been related to it. Prefer not to say what I said
What do you think this guy meant when he told me this?
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