I think that I have reached an important point in my efforts to improve my swimming. With all things that require mastering a skill, motivation is very important. For example, I find the incremental rewards of learning to ski are completely outweighed by the frustration associated with falling down or losing control: the only time I really enjoyed skiing was the first time, when for zero investment I was able to career down the mountain (in albeit a very dangerous fashion). I've never managed to learn to play an instrument because I have been unable to get over that initial hurdle of being too crap to care. It's not for lack of want but rather for lack of perceived progress. And this is something that swimming makes difficult to gauge as you can't see yourself swim, it's difficult to measure how fast you are moving or how hard you are having to work and, if you look at other swimmers, it's impossible to know how much effort they are putting in compared to you.
Having said all that, I notice that most of the time I am now one of the people swimming fastest when before I was one of the slower swimmers. If I make an effort I can now keep up with anyone I choose although I suspect I still have to make more effort than the best swimmers who share the pool with me. The point is that I have noticed (as has Luis, my swimming coach) that I have made a distinct jump in speed. It is normal that this comes at perhaps an exaggerated energetic cost as it will take time for my muscles to adapt to the new style, just as it did when I changed my running gait.
Coupled with this is a change in attitude which I think is what really marks a new phase. Previously, if someone pointed out that I wasn't keeping my left elbow up (for example), I would think "Oh, not again! I still can't get that right even though I am thinking about doing it right. This is impossible. Why is it so important anyway?". Then it occurred to me that even the best swimmers in the world probably have to continually be reminded to work on their faults. The point is that it is all relative. Of course my left elbow position needs working on but it is getting better and I am able to maintain it for longer. I no longer see this kind of thing as something negative but rather something positive, that there is still margin for improvement.