Some opportunities only come once.
If you are at secondary school or university right now, remember this: you will not get the chance to go back and redo that period.
What I used to believe, wrongly
I assumed that school grades and university grades had nothing to do with whether I would succeed. Selective school or ordinary school, what difference did it make?
Reality turned out to be entirely different.
The effort you put in at school shapes which doors open afterwards. Not because a grade measures who you are, but because it decides which starting line you get to stand on.
The part that stings
Nobody told me. Or somebody did and I was not listening.
Which is why I am writing this. Someone may be at exactly that point and may listen.
You can still do a great deal later
You can take a master's. You can take a doctorate. You can earn very well.
What you cannot do is return to that moment, with that much time available and those particular options in front of you.
Given the chance to do it again, I would do it very differently.