When I was ten years old I was proud to have memorized lots of odd things like the name of the highest peak in Sri Lanka or the capital of Honduras . Now 50+ years on I still remember them because I wanted to remember, but I honestly can say nobody ever has asked me for it . I also learnt 5 languages , because I wanted to be able to communicate or just understand what was written there. I never used mnemonics , I always forget them.