I seem to have very low patience with paper and pencil, which I find odd considering that I enjoy pixel art. With pixel art I can spend hours on a piece... however when I try to draw on paper I seem to want to get it over with as fast as possible. I rush through, I don't spend enough time cleaning up as I should, and I just don't seem to want to put the effort into it. It doesn't seem subconscious, but it seems like while I'm drawing I don't seem to want to put the effort into things like accurate lines, and I get bored fast.
IMO artists do three things that allow them to do what they do - the see things differently, they make decisions about what they will represent and how, and they translate those decisions through a medium.
Try switching up your 1)work-flow 2) your subject matter, or your 3)media for example:
1) Go find a good book on drawing, and re-start from the basics, if you sketch with line-art, try starting with mass or volume or value studies, and proceeding from there. You will likely make new connections or find it was your work-flow that was broken.
2) Grab a big sketch pad and head out, draw things you normally pass over, like one of R Crumb's things that he paid attention to was the power poles and electrical lines in his city images. It might just be that you are bored with your subject matter. Talk to/read about other artists and find out how they see the world. There is a fantastic book about new drawing practice called 'Vitamin D - New Perspectives in Drawing
" put out by Phaidon which is likely in your local bookstore - have a look. Also there are probably cheap, or depending on where you live free, open model drawing sessions - try attending one of those.
3) Switch to conte crayon, charcoal, graphite stick, or india ink, and wrestle with the medium a bit. It may be that your technique is too, well, technical. You may find, as I did, the you just seem to click with one (for me it was crow quill and india ink.)
Finally, a lesson from pixel art, use all of these things to start imposing restrictions on a drawing piece before hand - you may find that the structure of having certain decisions out of your hands re-invigorates your love of the process.
Also I tend to agree with 9_6 that while I do 'inspired'-feeling by seeing work that I like, it does tend to jam me up creatively.