I remember when Java was a curiosity. Then I remember when it was going to become the universal language of everything. Then I remember when it actually got used. There was about a 15 year period these events were spread among.
Of course, a good programmer knows how to learn any language. They were ready when Java actually got used.
I remember when the cloud was a curiosity and virtualization was something people only talked about. Now everything’s cloud, and there’s at least less B.S. and more actual functionality. That took about ten years.