If you had a fulfilling life, you wouldn't feel the need to accuse other people of being secretly unhappy.
Imagine: You have a different notion of happiness than most others, so people constantly tell you that you're not happy — even though you are. Naturally, you'll get defensive over time, but then those same people will see that as a sign that you're in fact not happy. Catch 22.
In other words: stop being condescending.
The real reason for this is that we take such large jumps in maturity after school stops holding us back that, in retrospect, we realize that if we hadn't been such fucking idiots in high school, we could have had it all.
I found out that it wasn't really school that was holding me back, it was me. I'd thought that it was really technical skills that were key to doing world-changing things with technology. But it turns out it's not: it's character traits like determination, perseverance, curiosity, observational skills, patience, listening, social skills, respect for others, and the ability to accept help that matter most. There's no way to develop these skills other than time and practice, and I found out that that was what my mostly-liberal-arts education had been trying to teach me, except I hadn't been listening all that much because I was so consumed with the technology aspect.
"I didn't have a happy high school years so how can she?"
I'm projecting projecting high school sucking?
Au contraire - That would require me to doubt everyone making claims that high school was awesome, which I am not doing.
For reference, my own high school experience was mixed to be sure. Parts were amazing, other parts sucked. I don't know anyone whose high school experience was 100% awesome. But I do know a lot whose experience sucked 100%. And those people often broadcast statements to the contrary.
He never made a claim that he had an awesome high school experience, and I'm not doubting that claim.