I plugged a 6pin connector that fit into my 8pin CPU power connecter (i've seen many build videos where people did this) and when I turned on computer cpu fan didn't work. PSU and case fans turned on for a few seconds and then the smoke came. smell of electric fire and crushed dreams filled the air as I realized I had ruined 5 years of saved up money. I scrambled to turn of PSU before it was too late. I half-heartedly unplugged 6 pin and put back the normal 4pin and turned on my system. Nothing wrong. everything works fine. please explain what might of just happened and why god decided to have mercy on me and let my computer work. I don't know either to be happy or sad.
1. Whoever you saw plugging a 6-pin connector into the CPU-power plug did not know what they were doing. There is a reason they are different and you stumbled on that reason.
2. The fact that everything still works is very surprising, but I wouldn't be surprised if you drastically shortened the life of most of your parts, especially the one that produced the smoke (guessing power supply). If there was smoke, something burned up, and something isn't operating like it should anymore, and that is likely to be the first thing to fail (and possibly take the rest of your system with it).
Sorry to be so glum, but plugging a 6-pin connector into the 8-pin spot was just a bad idea. Next time please, please just ask questions before you charge ahead. Even if you think it's a stupid question it's still better to ask, we are happy to help. I really hope it keeps running for you, but I would be ready for it to die anytime.