When experts tear your work to shreds.

Chagen

There's always that dilema. When you are doing a niche hobby, people who aren't well-versed in that hobby are always impressed by your work. Then you show your work to experts of that hobby and they critique the hell out of it, and you realize that it sucks. http://aveneca.com/cbb/viewtopic.php?f=6&t=1383 ^ I realized that with conlanging. Looking back on it, I was too hostile and violent to them. I don't bear any ill will against them, but it is depressing realizing that your supposed magnum opus is actually not very good.

Lisztening

On the bright side, it helps you realize what you need to improve. The rest is up to yourself, whether you want to take the steps to improve or not. Few people, if any, are born good writers. From what little experience I have from doing some writing myself and from seeing other people's progression, it's all about doing large amounts of practice. Tedious but sadly true in most cases.

MadassAlex

It's especially awful with any form of art, because you pour your heart and soul into it. So you have to keep doing that until you get awesome.

MoeDantes

One inspirational story I like to keep in mind:

Erle Stanley Gardner's first book was rejected by every publisher he sent it to. One of them accidentally included the reasons why with the rejection letter (this is not normal practice), so Erle improved the story, sent it back to the same publisher, who published it basically out of embarrassment and guilt.

Gardner went on to create Perry Mason.

The moral is: your first book always sucks, but its not gonna be your defining work, so keep at it.

Chagen

While creating a book is rather different from making a conlang, I guess you're right.

Icalasari

Experts don't need to do that with my work. I do a good enough job of ripping into my work on my own