You'll learn a lot about yourself when you travel solo. That's my #1 reason for recommending it.
Remember when you were a kid and went away for a week to your cousin's house or maybe summer camp? You felt kind of homesick for your friends and routines for a few days, and then you started loving the new experience, right? By the end of the week you probably didn't want to go home.
Solo travel is like that. It might take some getting used to, but done the right way you'll love it!
Traveling solo is your big chance to follow your instincts, to meet new people, and to get inside your own head.