I'm 20 and I've felt the same way. I just returned from a semester abroad and effectively took a 6 month break from all coding following my 7 years of continuous interest. When I came back to the states to start my summer programming job a few weeks ago, I was hit with a feeling of emptiness and mild depression. The reasons for this are likely tied up in my reverse-culture-shock, and the fact that I spent a majority of my time in India socializing and exploring. I came back to my home, to a job I was really looking forward to, and didn't find programming to be very fun.

To find traveling enjoyable and purposeful, you have to become a bit of an extrovert. My days were filled with interesting sights, sounds, smells, and people. I felt happy to have learned a bit more about the "real" world around me. Then I came home to a desk job, where I unenthusiastically wired up programming logic to produce results. A few days ago I realized the obvious reason why I was feeling down. I had planned my summer around my work, and I wasn't enjoying my work, because I was still searching for external reward. To enjoy programming again, I would have to dig deep and remember why I loved programming in the first place, and promote the introvert was suppressing in myself.

I told myself to forget that I'm working on a product that might not improve the lives of tons of people, or that my code might be obsolete by the end of the summer, or that outsiders find it hard to relate to stories of my progress at work. Instead I allowed myself to enjoy building cool stuff that would be mostly divorced from the physical world. It's worked pretty well for me so far. Reward is relative, nobody can tell you that you should find less reward in designing fascinating and complex sand castles in your mind than more normative tasks like socializing.

The takeaway I'm going for here is that if you're feeling burnt out, it might be because your motivations for programming have been messed up by social pressures since you started.