OK Coach... where I come from "left job on bad terms" means you got fired. Oh wait! We are talking about dummies here. My bad.
In my case, I frankly admitted I'd left because I was over my head, couldn't do the job.
It was accounting. Originally it involved no telephonic communication, but as time went on (I was there about four years), the position evolved into a lot of communication via telephone. Being a good soldier, I bluffed and insisted I could handle it. Well, I gave it the Boy Scout try, and got drained, wiped out. It was just too hard.
But as it was an office job, I didn't feel badly about having to give it up, and gave my 30 days' notice and left, going into another sort of job--not even remotely similar to this one--where someone else had the chore of dealing with telephonic communication.