When you decide you want to become an author, there are various stages of achievement.
Step 1 is simply to finish writing a book length book - it's bloody hard and if you manage to do that, be proud.
Step 2 is getting an agent. Querying (the process of finding said agent) is hard, demoralizing and takes forever. There's a real art to writing the letters, summing up a book in a few sentences. But the real challenge is in the waiting to hear back from agents. They are busy people with existing clients who take up 99% of their time so potential clients aren't high on their list of things to do. I hated the process, even though I had a good converstaion rate of requests to read partials, and full manuscripts. Hell I did so well I got an agent! And I'm so glad I don't have to go through it all again.
To give an idea of how long you can wait to hear back from agents, only today I got a response from an agent regarding SWITCH/BLADE from a submission I sent off about six months ago. It said: "I must apologize for the lateness of my reply. I try to get back to authors within six weeks, but sometimes that isn't feasible. With that being said, I want to thank you so much for sharing SWITCH/BLADE with me. I found your story to be very strong, and it drew me in right away. You have talent, but unfortunately, I didn’t fall completely in love with it in the way that I need to in order to take it on. I do want you to know that it was very hard for me to pass on this project, and I’m certain that if it hasn’t already found a home, it will soon. I wish you the best of luck on your writing journey."
Now that's a really nice rejection note and got a nice thank you note back from me because that's the right thing to do.
Of course, step 3 is getting published (or going on submission) which is whole different ball game.