Bollywood actress Preity Zinta, who went to the prestigious Harvard University in the US for a brief management course, says she had great fun being a student.

"Harvard was an amazing experience. Knowledge is key to any door in life.

Sometimes when you step back and go back to school, you look at life differently. It was great being a student, not taking any thing for granted and it was great learning new things, " Preity told reporters.

The 34-year-old went for a short executive course in negotiating and deal-making.