All Talk. Lot's of Promises and No Action

In the few years that I’ve been wholesaling houses I am continuously getting calls from people claiming to be buyers and give me the fast talk run around that they were going to buy my house and close in a week & it was a done deal and to send over the contracts, and then I wud never hear from them again.
It has happened 3 times in the last few days. And a good percentage of them are Realtors. The legit buyers are more conservative, they seem more relaxed and express a mild interest and ask to see the property and then when they call back they want to negotiate.
The flaky buyers offer almost full price, talk fast and give me a lot of promises and they seem like they are jacked up on energy drinks or maybe even something stronger.
I did Construction for many many years and it was rare to get cheated and get the run around.
But this Real Estate game has different rules. When thousands of dollars are at stake you better not fall for every hook & line, or you will be reeled in like the ignorant guppy you are.
I’ve been wham bammed, cheated, lied to, screwed over and goosed around till I’ve learned to keep my mouth shut, ears open, stay on guard and have every thing in writing all the while being the friendly easygoing, unintimidating smiling guy next door type.
Of course, 99% of the time people are trustworthy and honest, especially when you have every detail written down in a specifically worded contract.
Anybody else experience any dishonest or flaky humans? Or am I just being negative & paranoid?