Making the right decision at the time but later finding out it was the wrong one just seems like a proclamation that it's better to be lucky than smart. I get what you're trying to say, which is finding solace knowing you did what made sense given the scenario at hand, but it ultimately says you can do the right thing and be punished and do the wrong thing and be rewarded.

That said, I still agree with OP - it's good advice not to put too much stock in stock (unless it's liquid).