Describe Bill Gates success story. Why has Bill been so generous to the University of Washington?

I think this is from the text. I will put the source link below.

"You already know how Microsoft was founded. Bill Gates and Paul Allen dropped out of college to form the company in 1975. It’s that simple: Drop out of college, start a company, and become a billionaire, right? Wrong. Further study reveals that Gates and Allen had thousands of hours of programming practice prior to founding Microsoft. First, the two co-founders met at Lakeside, an elite private school in the Seattle area. The school raised three thousand dollars to purchase a computer terminal for the school’s computer club in 1968. A computer terminal at a university was rare in 1968. Gates had access to a terminal in eighth grade. Gates and Allen quickly became addicted to programming. The Gates family lived near the University of Washington. As a teenager, Gates fed his programming addiction by sneaking out of his parents’ home after bedtime to use the University’s computer. Gates and Allen acquired their 10,000 hours through this and other clever teenage schemes. When the time came to launch Microsoft in 1975, the two were ready. Gates credited much of his success to the University of Washington hence his generous gifts."