I was in Tokyo on business once. It was a last-minute thing, so I didn't even get the chance to learn a few phrases & read up on culture. I ate alone, shopped alone, joined a city tour alone (was adopted by a young boy in our tour group!), got lost alone, found my way back alone, etc. What an adventure!I'm doing my second solo trip soon, and similar to what was said above, I got a couple very interesting seats at restaurants because one person is easier to seat than multiple - at Jiko I got to sit right at the bar where a lot of the appetizers and small plates were made, they were cooking it right in front of me! I had an amazing time chatting with the chefs, and they gave me a bunch of small freebies to nibble on. Solo at Disney is wonderful, especially if you've been before and know your way around. And truly no one cares if you're alone, I'm not certain anyone else takes the time to notice who is alone and who isn't.
Bottom line, if anyone is on the fence about whether to go solo, DO IT. I will bet serious money that you will never regret it.
And the sweetest part was that every morning, the staff in the hotel restaurant sat me facing a window so I could have something to do while I ate. I had brought a journal & wrote & ate & people-watched. I did just fine, thank you very much! And met some amazing people, some of whom spoke English & many of whom did not.