Hi Michelle
First of all I wanted to say, what a great question you ask of us all. "What motivates you to improve?", I hope this question gets a lot of answers. It may help those who are out of sorts to help them get back playing too, as we all have times when we stop playing.
With that in mind, I have a lot motivating me at the moment. In the run up to Christmas 2015 I decided that when family asked me what I wanted for presents I would ask for funds towards music related purchases. My birthday is 3 weeks after Christmas, so I did the same there too. All my family know how much I enjoy playing guitars and making music, so they know cash towards music presents make me very happy.
So after Christmas and birthday, I was able to buy a Focusrite Scarlett Solo Audio Interface, as my previous one was dying a slow and not silent death, and a MIDI Keyboard. I have the Audio Interface up and running, and it sounds fantastic. It took a bit of tweaking to get it working correctly but its running as clear as a bell with minimal latency. The MIDI keyboard is up and running too, its a steep learning curve but a lot of fun.
Buying both of these got me motivated to get back into playing guitar more, I'm now back playing pretty much every day, back learning Tommy Emmanuel Boom Chick Style stuff-its very slow going but fun. I'm starting out on theory too, its a huge challenge for me as I know nothing, but everything I remember helps my playing.
Having the Audio Interface and the MIDI Keyboard made me realise that I didn't really know that much about how to use the DAW I have, which is Reaper. So that had to change, and has changed, I've learned so much in such a short amount of time, and realised that Reaper is as easy or as hard as you want it to be. Mine is now customised to the way I work, with templates and actions, so its so much easier to use.
So what motivates me, setting challenges-whether I complete them or not is immaterial, its the knowledge I gain in trying that's the main thing, improving my skill set and having fun while doing it, enjoying playing the guitar and knowing when to put it down so my head can process all the new knowledge.
After all that, I gotta go play now, thanks
Joe