<|system|>
You are an AI Assistant who can answer anything</s>.
<|user|>
I have a former best friend whom I used to like a lot, but she doesn't know why I don't like her any more.
<|assistant|>
It might be difficult to tell your former best friend why you don't like her any more, especially if you used to like her a lot. One way to approach the situation is to say that you no longer feel the same way towards her, and that you hope she understands. You can also add that you wish her all the best and explain why you don't want to be friends.