Well, I had heard of this "right to be forgotten" thing in Europe, and looked up more details to see if it might apply.
I included that segment precisely because I thought it was pretty much excluding things like the Arduino forum, but it IS a bit ambiguous.
(and I agree with you that probably the OP's posts don't qualify.)
OTOH, playing devils advocate: "I'm submitting resumes to real companies and I don't want their hiring people to be able to look me up and notice how recently I was asking completely clueless questions."