It's an old adage, but one that is especially true of writing: If at first you don't succeed, try, try again. That second "try" is key—and there are many more "tries" to this truism when it comes to writing. Want to know how many tries it took me to get an agent? Read my interview at QueryTracker.net:
It's a few months late because my response to the interview questionnaire got lost in cyberspace, so I recently had to try, try again. ;)
If you're still on the road to getting an agent, I hope hearing about how long I spent on it will be more encouraging than discouraging. Part of the reason it took me as long as it did is that I gave in to despair too many times along the way. But as one of the "infernal proverbs" in William Blake's The Marriage of Heaven and Hell says,
The road to excess leads to the palace of wisdom...for we never know what is enough until we know what is more than enough.
At least now I know how much wallowing is more than enough. Not that it stops me from wallowing in the Slough of Despond every time my manuscript gets a rejection from a publisher, but I plan to keep on the road, slough or no slough, until I get there.
I guess all this is a roundabout way of saying that if you really want to be a writer, you have to be a glutton for punishment. ;)