I realized something today. You never stop learning in this business. Hell, I think I've forgotten more than I've learned, but either way, each day is a new day to learn something new. And I'm here to tell you that an old dog CAN learn new tricks.
I looked back on a previous project I worked on. It had only been about 6 months or so, but I was using some techniques and technology that I was fairly new to me at the time. Not that the project wasnt good; the client was very satisfied, but to my (now developed) eye, I can see some things that I would now do differently. You see, since that time, I've done similar projects and I've learned a lot. I have developed "standards" that I hadnt had before. I organize my thoughts and planning in a different way. My entire approach is different and because of this I can see a dramatic difference in the quality of my work.
I guess this holds true to just about everything in life. The more repetitions, the more automatic it becomes. The more experience - the more lessons learned, the better the results.
I cant go back and re-do those projects, but I can (and will) take each new challenge as an opportunity to grow and learn.