For sure, especially since if your facts/conjecture based upon half-remembered things you heard nearly a decade ago are right then you can pat yourself on the back, and if they're wrong A) most people probably won't know and B) it'll make people people who do know angry.
Disinformation on the internet is rampant, so sharing unverified facts is sort of like littering onto a random lot that's already piled with garbage and overgrown with weeds: you know it's still not the right thing to do on principle, but if reaching a trash can is inconvenient enough and it's only a small amount of litter...
Calling people fat you should just do because people are fat and they need to be reminded.