For me, it was when I had been a member for a couple of years, and lurking for a while before that.
Someone was making suggestions about contacting

about making {redacted}, which I'd already tried and actually managed to get a few replies.
An older forum member basically told him off.
I very n00bishly assumed that since the older member's postcount was only 100-ish, they must be new, and had no business telling off another forum member that I was familiar with.

I present:
That time when I {basically} called BlueFlames a n00b. (I actually said he reminded me of a forum member (Takashi) who was extremely annoying and IIRC eventually got banned.)