Conceit is the enemy of good design.

Onur Cobanli explains:
Everybody likes their own designs, but this can be a mistake. Love is blind, and an excessive fondness for your own work can lead to conceit, which ultimately hinders the creation of truly good design. A high opinion of your own designs can blind you to its flaws. Being overly confident or conceited in design thinking prevents learning and adaptation, which are crucial for creating effective and appealing designs. It is okay to dislike your work, that's how you make better work; you dislike it, then you make it better, and it is also okay to like your work, you like it, you work on it more and you make it perfect; what I am saying is that initially, even if you feel yourself as a great designer, it is okay to doubt your work, it is healthy to doubt your work, a small amount of doubt is healthy but a small amount; you should of course also trust your work, and you should embrace this duality to make it perfect.