Answer:
Though I should be unique, you've made most of us the same. I would be stronger, if my characters were stranger.
What cleans as it gets dirty only to get clean the more you use it?
The more you have of me, the less you see. Who am I?
People in love are often bound to this.
If there are three cups of sugar and you take one away, how many do you have?
My days are numbered.