During swimming lessons especially for beginners you’re encouraged to start from the shallow waters. But there would come a time when you be asked to try the pools with deep waters and there you would realise they are out of your depth you’re used to.
They are out of your depth because you have not developed the skills and muscle memory to swim there and it does not also mean you can’t learn and swim there like others. You just have to be patient and gradually with the right guidance you could enjoy there even more like the swallow waters.