I also cannot swim last time. Only after army, then i learn how
to swim lol. Preseverence is the key. You also need to get rid of
your fear of water. Learn to relax, study how people swim.
I learn swimming by myself. I just go to swimming pool and observe
one holiday. I spent 2 weeks going to the pool everyday and
observing. Then i finally learn breaststroke, followed by
freestyle. Butterfly is beyond my comprehension though.