I think that there may be a variety of definitions of 'positive thinking' - and its' power.
I believe in thinking positively - when I can... and have had good results.
I also try to stay from those who are 'negative' - as they will try to suck any 'positive' energies from an individual.
Not sure if this makes any sense... I have been teaching this to my wife - and she also is a believer in the benefits of 'positive' thinking - and attitudes.
One reason I am not keen on 'negative' people is that I was raised in a 'negative' environment. An example of this...
I wanted to design, build and market flashing LEDs when I was a teen. (I actually built a few 'prototypes' that worked, too.) Instead of encouraging me (positive energy), all I got from my own family (siblings) were comments like "Who would buy that?" or "What happens when the battery runs down?" or "That's stupid!" or "That's dumb!"
Well... I didn't pursue this direction. Nowadays, what do you see all around you? Flashing LED products. What happens when the batteries run down? Who cares? By that time they are ready to be tossed - or can be replaced.
Anyway - there have been many 'negative' influences in my life, until I realized what it was - and now will 'shun' any negativity - if possible.
This may not be what you were describing...
Regards,
Jim TX