truck doesn't start anymore

[Savage]

last night i was parked at a gas station with my truck off (not putting any gas in it, just waiting with a friend to get gas in her car) started it up and drove off. well less than a quarter mile later the truck shut off so i was rolling in traffic now. i tried to be quick and start it with no luck. it wasn't until i came to a complete stop in the middle of the road with no shoulder to be in that it started back up. so we continued on our way and less than 15 minutes of running time it did this to me again but this time in a parking lot. however this time there was absolutely no possibility of it starting. another friend came to jump it (despite there being no real signs that there is anything wrong with the battery). this failed until about 5 minutes later and a whole lot of revving his engine, mine finally started. i drove it straight home (and the whole way it sounded different/like it wanted to shut off again). now it's the next morning and to no surprise the truck will not start outside my house

what makes this weird to me is the fact that the whole time all of this was happening last night, my lights/radio were on. and the voltmeter says the battery is fully charged.

could it be spark even if the truck was already running/driving when it first shut off?


tl;dr
my truck shut off on me twice while it was driving. now it won't start at all. apparently the battery is full charged.