The surface attitude of saying "I don't care" actually says the opposite. If I don't care that much, I don't need to emphasise it, do I?

Hmm, yes, I suppose not caring also equates to apathy in a way. Perhaps it would have been better to ask "does it matter?" or "does it need defining?"

Ones own achievements can be outstanding on some occasions but they are that way because the rest of the times they are not

Absolutely and by the same token those who stand out do so because they are different to the average/mediocre person. Yet don't we just love the underdog! Those who suddenly stand out due to their persistence and hard work, despite what others thought of them. It's almost a testament to the fact that we all want to feel special and stand out at some point. Which would lead me onto a whole other topic I could write about if I could find the time. 😅