You should write

There is more than one reason to write. 

If you are thinking about something all day, and then suddenly, a light bulb goes off, chances are, you could help someone have a similar experience if you write about it. 

Writing allows you to spread ideas worth spreading. But it does something else as well:

In your attempt to teach others, communicate your ideas, and help people change, the person who might benefit most from your writing, is you.