When I started in software you could sit down with any programming language's manual and begin coding in no time. Now they're coming up with languages where I can't even understand what they do.
Same here. I haven't done software development in over ten years now, having transitioned into managerial and consultant roles. I can understand the fundamentals; that stays pretty much the same. But it's not as straightforward nowadays to get a grip on how some of the new languages function. I would say the biggest learning curve are the development environments. When I started coding, those were either non-existent on in their infancy. Nowadays, things like MS Visual Studio and Eclipse are quite complicated. They certainly make for a more efficient coding experience once you understand them. But its a big learning curve.