If anyone here has a PhD, can you share with us what made you decide to get a PhD?

Was it because

- better salary
- prestige
- job promotion
- genuine academic interest
- you didn't know what to do with life & you had a sponsor
- your father told you to

I did ask a couple of PhD's in real life. One said prestige, the other said better salary... which she now regrets becoz a lecturer's salary really sucks.

Does anyone really go for a PhD because they were truly interested in the knowledge?