1．It’s true that I dropped out of college to start Microsoft, but I was at Harvard for three years before dropping out — and I’d love to have the time to go back.
It’s true that I left college early to start Microsoft, but I was at Harvard for three years before I left, and if I had the time I’d love to go back (for my further study).
2．Since you are a success, my students perceive that as a reason not to care much about getting a good education.
As you are a success, my students tend to infer from your success that they don’t have to worry very much about doing well in school.
3．But somebody handing you a book doesn’t automatically foster learning.
But if someone gives you a book you may not necessarily learn anything from it.
4．In high school there were periods when I was highly focused on writing software, but for most of my high school years I had wide-ranging academic interests.
Sometimes in high school I engaged myself wholly in writing software, but most of the time I studied a large variety of subjects.

5．One parent wrote me that her 15-year-old son “lost himself in the hole of the computer.”
One parent wrote me that her 15-year-old son became completely preoccupied by the computer and ignored everything else.
6．... teaches you first-hand about group dynamics.
Group dynamics is the way in which the members of a group behave towards each other. In group activities we can observe how different people interact.
7．It’s fine to take a deep interest in computers, dance, language or any other discipline, but not if it jeopardizes breadth.
It’s OK to be very strongly interested in any subject or activity such as computers,dance,or language,but not if it makes your interests too narrow.
8．If you fall into an obsessive pattern in high school, you’ve got two problems.
If you fall into a bad habit of having strong but narrow interests in high school, you have two problems (not just one).

9．... unless the specialty ends up a dead end.
... unless there is no future for such a specialty.
10．Graduate school is one way to get specialized knowledge, although extended college education isn’t always a good investment from a purely economic standpoint.
Graduate school is one way to study a particular academic area, but it may not be the wisest way to invest your time and your tuition money.