IndependenTraveler.com had a good review of why and how Solo Travel.
Although I rarely think about NOT traveling because I prefer to go solo, others may be thinking of their first trip. This is a good read from Independent Traveler..................
Single Travel: Tips for Going Solo

Of course, single travel has its perils too -- such as safety concerns, loneliness and the dreaded single supplement. But a little preparation and common sense can save you money and get you through the rough spots.
Why Travel Alone?
Solo travel can be the ultimate in self-indulgence; you can rest when you want and pour it on when you're feeling ambitious. Another benefit is that your mistakes are your own, and your triumphs all the more exciting. There's no worrying that your insistence on trekking all the way across town to a museum that was closed ruined your partner's day; it's your own day to salvage or chalk up to a learning experience.
Also, you can do exactly what you want to do -- all the time. Always wanted to try surfing? Sign up for a class and go for it; there's no one sitting on the beach bored while you have the time of your life. Have no desire to see Niagara Falls? Just drive right by.
Safety First
Perhaps the foremost concern of the solo or single traveler is safety. Without a companion to watch your back, you are more vulnerable to criminals and scam artists, as well as simple health worries. But the saying "safety in numbers" isn't necessarily true -- a solo traveler can blend in more easily than a group, and not drawing attention to yourself as a tourist is one way to stay secure. Here are a few tips:
- Know how long it takes and how much it costs to get from the airport to your hotel or to the city center. Solo travelers are more likely to be "taken for a ride," so ask the taxi driver how much it will cost before you leave. If it's considerably different from what you know to be true, take a different cab.
- Find out if hotels at your destination are open late, so you don't end up sleeping in your car or worse.
- Be your own best counsel; if it doesn't feel right, don't do it.
- Carry good identification, in more than one place.
- Keep to open and public places, especially at night.
- Exude confidence and walk purposefully.
Trust Everyone and No One
One of the best reasons to travel alone is to meet new people, but this also makes you more vulnerable. It's okay to hang out, travel and share with new friends, but you might not want to ask them to hold your money. Scam artists can often be the most charming companions you'll find; you want to be open-minded, but keep your guard up enough to ensure your safety.

Frequent solo travelers are all too familiar with the single supplement, which tour operators, cruise lines and hotels tack onto your bill to make up for the fact that they're not making money off a second occupant. The supplement can range anywhere from 25 to 100 percent of the trip cost, meaning that you could end up paying twice as much as someone traveling with a partner.