There is a really wonderful circular relationship between self-esteem and traveling. When you travel alone, you travel on your terms. You get to do what you want when you want. You can connect with people if you wish or avoid them completely. Those are the obvious benefits for going solo as a traveler. But there are many other benefits of solo travel that affect your whole life. The experience encourages you to stretch and grow as a person. You gain a lot of confidence and get better at problem solving. Your behavior is reinforcing a positive self-esteem. As your self-esteem grows, you start engaging in more independent, self-serving behaviors.
It's been years since the first time I traveled alone to explore a city. The truth is that the idea of traveling alone has never given me fear or a feeling of rejection. At the age of only 10, I already found myself getting on a plane alone traveling from house to house of parents who lived in different countries. I guess traveling alone is an obvious acquired taste given my solitary and independent personality.
There is nothing better than traveling alone and having your camera be your company, being able to dedicate as much time as you want to taking a photo, getting up at the time you want to take advantage of the dawn light and take photos when there are still no people or at least few walking around the city or a town. As a photographer, if you travel with someone who does not share your artistic passion, the trip can quickly become anything but to your liking and you will feel self-conscious when thinking about your next shot.