GM GR

this is 'odd' to me; I cannot give an explanation - got an idea why? : The battery gauge read fully charged today, but still a 'no start' at turn of key. so I 'fiddled' with lights to see if they dimmed while turning key... - didn't appear to. The parking lights were left on (unintentionally, but nevertheless...) while I went into the house for 10 minutes or so. I tried to start the truck again when I returned. It started !! that is 'odd' - what in the world - why ?? The entire thing was repeated when I returned home tonight. The truck did not start. I left on the parking lights for 10 minutes after which the truck was successfully started. .. huh ? What IS that ? (what am I 'really' doing ?)..... do you have any idea, perchance ?