Unless you're a BIG NAME writer who has hundreds of fans camp out at a book signing, no, the writing life is not all that glamorous. It's a job, just like any other, and while generally an enjoyable job, it's still a job, none the less.
Writing professionally requires craft, that is, you've got to know the tools of the trade and how to properly use them. A rough draft might be created willy nilly with no heed to craft (which is unlikely for most pro writers), but then at revision time, one must know how to sculpt a good story or novel from thousands of words and hundreds of pages. It takes skill, dedication, and talent.
Then you have the most unglamorous part of writing: the waiting. Waiting to hear back from editors when you submit short stories, waiting to hear back from literary agents when you're trying to break into the biz, waiting to hear back from said literary agents when they request a partial (part of your manuscript). Very often this waiting is not days or weeks, but months. In some cases, even years. Waiting is hard. Many would-be writers give up when they have to wait so long. And very often what you get at the end of the wait is rejection. So we have to have a tough skin and believe in ourselves.
Another not-so-glamorous aspect is having to self promote. Nowadays it's not enough to just write a good book or story, you've got to be your own marketing director and publicist. Most writers write because that's what they love and do well. Very few of us know much about effective marketing and publicity. I mean, people get degrees in those things! So, we have to join Twitter and follow Facebook and develop websites and write blogs (like this one) in the hopes that someone out in cyberspace will notice us and purchase our products. With the growing popularity of self electronic publishing, you can add to your list of writer tasks formatting your book for electronic publication. Believe me, there's more to it than just just uploading a Word document.
Writing is also a lonely occupation. That's why I teach fitness classes. It gets me out around people who very often inspire characters and stories. Otherwise, I'd be cooped up all day with just the dogs and cats for company. Not always the best thing for one's mental health.
So, if you think the writing life is for you, then by all means go for it. But just know, it's not all sitting around writing whatever pops into your head the live long day.
It's a job. But for me, it's the right job.