I think in order to really be productive and enjoy guitar playing is to not just learn about it but create from it. Whether or not you are good at the 'creating' part is not really important. Just sit down and start noodling some riffs and licks and start hearing stuff you like and build something from there. Part of my playing is fleshing out ideas. Since I'm doing for the fun of it, I don;t have feel like I'm creating the next Led Zep song or anything but something that's nice to my ears. These little ideas keep coming around for a 'song' and I just run with it.

The point is that if you are just in learning mode all the time, it becomes a drill. Once in a while, you have to take what you've learned and let it do its things and just play.