I didn't need anyone to tell me I was smart. I figured it out myself. As you say, I was "smart" at the subjects I loved and not so much at others. Now, as an "elder", I tell those coming up If you want to be rich and-or famous, develop your talents. But if you want to be happy, work on your weaknesses: Become round.
BTW, If someone had told me life could be so good at 71 years, I'd have had more courage in my youth.