Yep, I feel like this sometimes. The development of a character is a give and take. Authors come up with various ways in which they are 'introduced' to their characters.
By dreaming about a character at night.
Day dreaming about a character.
Inspiration from a person in daily life.
An event.
An alter ego.
What ever the means is that a character is introduced. Sometimes development of the character is difficult.
HOW TO DEVELOP YOUR CHARACTERS
Since I am a visual person, I may go about this differently than most authors.
1) I find a picture and likeness of my character
2) I paste them on my screen or wall
3) I jot down three good qualities about them
4) I jot down three negative qualities about them
5) I write out what I want to improve in their personality
6) I play with their dialogue
7) I note their major moods
8) I list their 'ticks' or habit, repeated words they like to say
Once I've built this, I dive into writing. When I get stuck, I go to my picture and list of qualities for inspiration.