There Is No Problem That a Guitar Can't Solve
This is what I have found, anyway. Your mileage may vary.
Bored? No need for that if you've got a guitar. Either learn to play it or play it. Either way, the hours will melt blissfully away.
Feeling down? Pick up the guitar. Strum away. Find a soulful riff. Play a song that fits your mood. Write a song that fits your mood. Soon enough, you'll feel better.
Sick? A little music never made anybody sicker, and I happen to think it heals. I'd be willing to bet that modern medicine will appear as barbaric as blood letting someday, and I'll bet advanced medicine will involve making cells happy by playing the right musical frequencies.
Lost your lover? The guitar might not get them back, but it can help you feel better. It can help you get a new lover, too.
Pissed off? Plug in, turn up, rock out.
Need money? Pop open your case and sing your heart out. Sing a funny song about how bad you need money, and your case will quickly fill with the green stuff. Failing that, sing Bob Seger or Bon Jovi songs -- people love those for some reason.
I'm sure there must be some problem that a guitar can't solve, but I can't think of it. I guess the guitar doesn't solve social problems, but at least it tries. It does darn well with the personal stuff, though.
Do yourself a favor and learn to play the guitar. (affiliate link)