My most recent trip to Japan was the first trip where I didn't have any familiar faces in the area to reconnect with. It was two (glorious) weeks bonding with me, myself, and I. They say how traveling alone is reflective, about rediscovering yourself, blah blah....I don't know if it's because I'm already so used to being alone that it was none of that. Yes, it's lonely, but not in the depressing way that you may think. It's more of an annoyance. No one to take a photo for you, no one to eat that minimum two people order meal with, no one to share your excitement with, that sort of thing.
But would I travel solo again? Hell yeah, in a heartbeat! I love being able to do whatever I want whenever I want. I will also say though that some places are better than others for solo trips, and Japan happens to be one of the places I deem to be extremely solo-friendly. Another situation I ran into often was the following:
Stranger: You're traveling alone?
Stranger: *looks at me incredulously* You're so brave/courageous!
I always feel like the above reaction to hearing a female traveling alone is weird and unsettling. If I were on a business trip alone would you say that? If I were a dude would you say that? Plus does it really take courage to travel solo? I don't think so, not any more courage than eating out in a restaurant alone or going to a social event alone. What you do need to travel solo is independence. You need to be able to do things and solve problems on your own. If independence isn't a skill you already possess, then you DEFINITELY need to try a solo getaway at least once. It will definitely be a special experience.
Before going to Japan I was pretty worn out from two months of nonstop traveling. I thought that the travel "bug" is gone for sure and that I've met my travel quota for this year and the next. But actually traveling is like a hobby for me. Yeah, you may get sick of it after being constantly exposed to it, but you still love it and look forward to planning your next itinerary and researching countries.