I´ve almost always traveled with my partner, but I´ve made two trips alone. The first time I traveled to Vietnam, where I spent one month by myself, and the second time to Egypt for three weeks.
In my case, the experience was amazing. I have to admit that I have a perfect partner to travel with, but when you travel alone you have time to be with yourself and meet more people.
It´s a highly recommended experience. I think that you should do it at least once in your life.