I'd add one more thing to this article: don't throw these projects away, even if they seem failed/doomed/incomplete. Store them somewhere. Back them up. Whatever. You might need them.

Back when I was a teenager, I wanted to write an art package for an obscure computer (Acorn Archimedes). I wrote the first version in BASIC, then decided to re-do it in assembler. The assembler I first used couldn't cope with the size of the project in the end, so I wrote my own assembler; at that point I discovered C, so wrote it in that. Unfortunately the C compiler I used was so full of bugs I decided to port LCC to produce ARM assembler, but then I needed a linker, so I wrote that as well. Got it all working lovely to the point where it could compile itself.

At university I figured Intel PCs were more useful than my obscure computer so... I forgot about it. Lost it.

And to this day, I can't help but wish I still had it... I had written, and lost, a complete C development system, faster than any of the other compilers/linkers I tried, small footprint (it had to fit in a machine with 4Mb RAM), and ARM chips are now everywhere. Damnit!

So please... save your work.