Oil paintings- coming right along

Why is it that some paintings you toil over endlessly, working and reworking to no avail, never satisfied? Well that hasn't been the case with this new body of work. Maybe since it's been a while since I have devoted myself to oils, or maybe I'm just lucky right now, but these paintings have come so easily. It's the difference between swimming against the current and floating along in an inner tube down the Itchetucknee. One wears you out and mentally drains you, while the other you don't even notice you are going anywhere.