Keep your criticisms constructive...

I am not saying do not criticise, because I do it all the time, and I'll not forbear for fear of being seen to be passing judgment. But I'll try to keep my criticisms constructive, and I believe that's a good thing.

In my opinion, if you think others are doing it all wrong, and you truly care, do not stop short of putting forward a better or more viable alternative. If not, and if you do not know their reason(s) for doing what they're doing, for fuq’s sake, mate! Stop making noise and let them do their thing.

What people do with their lives is entirely their business, especially regarding matters that you're not entitled to be involved in or informed about. If they do it or think it wrongly, it's their lesson still, not your business. I hope that's clear.