Combine theory and lessons with learning songs that you would enjoy learning and playing. Either that or find a partner to learn and play with. Whatever you do, the key is finding a way to keep it fun and interesting while you learn. If it’s all work the guitar will collect dust…

Learn how to read. Play every thing you can on sheet music – learn to write. It is painfully slow at first, ut will open up new worlds.

oooh, I’m familiar with this, I couldn’t put my guitar away when I got it, and after a while the only thing it was good for, was collecting dust.
I think you got to bored with it, ehm I mean with that, that maybe it’s time for some new songs to play or another guitar style.
keep on playing!!

Keep playing, push yourself to do so. Try and learn something new everyday. Try and find people to play with as that’s the best way to learn.
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Try learning a new instrument. Not only will it open you up a lot musically, but when, after a month or so, you go back to the guitar you will find your style has improved/changed enormously. It doesn’t have to be so different, a banjo or other stringed instrument is not too different to play. I personally suggest leaning the piano. Good Luck!

Also, if you are looking to stick only with guitar, try learning some theory instead of just “tricks and riffs” as you said.
Good luck dude

Practice. Try new ‘styles’. Try composing your own tunes. Just don’t give up. Join a group who you can ‘jam’ with. There are lots of reasons you should keep on ‘keeping on’, so to say. Good luck.

Are you becoming interested in new things? Are you feeling a little down? Or do you need some more experiences to extend your playing? Go beyond. Maybe you are getting ready to create your own music through your own experiences. Or maybe you need something new in your life. You may be having something new come into your life. Open up, evolve, experience, and analyze. You have a gift that may be growing.

You more or less answered your own question, by mentioning the problematic nature of the guitar sitting, collecting dust.
To get over the “plateau,” you have to pick it up and practice.