The psychology of humility. Why do we not value our efforts?
According to this article, jealousy may cause a person to view themselves more as the person he is jealous of. So if you work hard, write great papers, etc. you may be jealous of another person who has similar attributes. Thus you would view yourself more like him. 

Also in social comparison theory there is the idea of upward and downward social comparisons. If you compare yourself to someone who similar to yourself or more "fortunate" than yourself, you will feel bad. On the other hand, if you compare yourself to someone who is less fortunate than yourself you will feel good. This is why facebook often makes people feel bad about themselves. They see people with trip photos and smiling photos and compare that to their "boring" lives.

Source

Changing Me to Keep You
State Jealousy Promotes Perceiving Similarity Between the Self and a Romantic Rival