Truck shaking after battery change?

I pulled out my battery to clean the terminals as they were corroded as hell. I had it out for a day, and I put it back in today and the first 3 times I started the truck, it was shaking and felt like the engine was about to die.
The battery is fairly new, and I Installed it correctly. I have started it about 5 times since, and it's perfect now.

I googled it, and it seems fairly common, but I couldn't figure out what caused it.

 

Normal.

Killed power to the ECU, it needed to relearn the idle fuel trims and butterfly position.
Wife's Rav4 is a bitch to even keep running after replacing the battery. 4 or 5 restarts and it's just fine.

 

^^^^This^^^^
ECU had a hiccup in the power supply and had to re-group.

 

Cool. I figured it wasn't something too serious since it was still running fine and there's no CEL. Thanks gents