Know When to sell?

One of the investor asked this "what is your exit strategy?" I told him i got very good answer in one of the book i am reading. I think these are very true and i would like to share with the readers.

Ideally, we'd all hold our investments forever, but the reality is that few companies are worth holding for decades. The author point out when you shouldn't sell ;)

1. The Stock has dropped.
2. The stock has skyrocketed
3. Did you make a mistake?
4. Have the fundamentals deteriorated?
5. Has the stock risen too far above intrinsic value?
6. Is there something better you can do with the money?
7. Do you have too much money in one stock?