I learned to sew on a single thread machine. It was a Wilcox & Gibbs and did not use a bobbin. I loved that machine, but you had to be really careful to end your stitching so that it would not undo. It was very easy to rip out mistakes, just pull the right thread and it's ripped out and you are ready to go again.
I had a bit of a problem later learning to use a bobbin, but when it's rip out time, I feel kind of nostalgic about my old Wilcox & Gibbs. I guess I am giving my age away with this tale, but 81 isn't that old! Is it?