Writing can be the most liberating feeling in the world. There are many reasons a person may choose to write, fiction or non-fiction alike. Some people aspire to be authors, and others do it to relax. There are endless reason to write anything, some of the reasons can be found within books themselves. Here are a few reasons that can be found in literature:

To express yourself.
You like the sound of your own voice.
To explore new worlds, or old ones.
To be somewhere else.
To make sense of ourselves.
To set ourselves free.
To get free of ourselves.
To show people what goes on inside our heads.
To make people laugh.
To get attention.
Because its all we know how to do.
To stop hearing voices in our heads.
To stop being anything or anywhere at all.
To leave our mark.
To create something that will outlive us.
To share something true.
To disappear.

Whatever reason you have to write, don't stop because of what others tell you. Do not stop because "authors don't make a lot of money." Because who cares. If you are writing for the right reasons, nothing can stop you.

Find those characters in your head, and don't let them go. Tell their story. You may learn something along the way.