When I first moved to live and work in Sweden in 1995 I had two ambitions. The first was to get a job working at Ericsson. My mobile phone was an Ericsson model that I was absolutely in love with and was much better than my previous Blaupunkt and Motorola phones. I just had to work for the company that made my new teddy bear. Unfortunately things did not work out. I found myself living in cold north of Sweden where there were no Ericsson offices or factories.

Ok,  here's my quick answer:

If you want to continue to learn for the future you should learn a language that has true parallel or concurrency support.  The onslaught mobile devices is only going to increase and soon the only way for any web server including those in the cloud to survive will be concurrency, parallel programming and distributed processing.