The 3F theory is indeed valid although I must say I have met people who have broken all 3 rules and are happily retired with all 3F's in place and a shed of cash. Their numbers can, however, be counted on the toes of one foot.
The thing I find most incredible, is that a common profession makes the person sitting next to you more believable than the taxi driver who gets you to the hotel.
In this day and age when someone uses flattery on an airline pilot...even if he is a colleague...excuse the cynicism...but I would be very wary.
You can only blame someone else if you refuse to do your own due diligence and make your own decisions.
Lecture over...but I still love the 3F theory...and my old man told me about it 30 years ago!