I've had days where I've spooked myself good.  Not always sure why - but some days I can just tell I'm not on my game.  Seems to be with the hotter or squirrelier models, but not always so.  What works for me is a short first flight and then, by the time the model is refuled and checked over I'm usually calmed down. 

Certainly when you're first starting out you're entitled to be a ball of nerves.  It will pass.  The good news is that the times I have dorked a plane it's usually not the day I'm cautious.  It's the day I'm feeling hot or just being careless.