The good thing about a hobby like this is we don't have to rely on other people. I started going to the gym with two friends, it was good, it was nice to learn together and help each other, but when they became more erratic, I decided I had to resign in my head that I would be doing this solo most of the time. But it's a great hobby, if I'm bored I read up on it, any learning experience tends to be a mood enhancer for me, and not relying on others was the right decision.
That's the logic I'm using with cycling now, I'm only just starting but my message to my friends is basically "I'm doing it, feel free to join in" not "Let's go cycling around Europe next year!" I'd prefer the latter somewhat, but my head is definately not there, I am 90% sure I'll be going alone and that is how I am preparing for it in all regards, including mentally.
Motivational "tips" tend to be either in the form of encouragement ("it will be fine/better than you think") or sound like some corny motivational seminar line ("Believe in yourself!" *wince*) - I tend to think that when I have worried like this in the past, it's pretty much always turned out good/fine.
I guess I'd agree with what Dayvo says, although I don't have the experience, that both solo and 1+x will be different experiences, but both decent/definately worthwhile.
All about experiences... add a solo tour to yours
p.s - Im going to buy a Kindle I think - befriend a book or two
