Let's say for arguments sake I have been using qwerty for the last 23 years or so, 15 or so touch typing. How much more efficient across my lifespan can trying

Let's say for arguments sake I have been using qwerty for the last 23 years or so, 15 or so touch typing. How much more efficient across my lifespan can trying to teach myself a completely different layout really be? It could be years before I clean out all the errors.