No, losses are not the only way to gain experience in forex but losing is the main way to gain experience in forex or we can say that loss is a more effective way to gain experience in forex. Most of the time we forget another experience but losing it is hard to forget. and, I agree with you because losses are not the only way to gain experience but you can get them from the net and we can also gain experience in trading on demo accounts and learning and reading will give us a good experience in this market