It's true, he helped you through your training and gave you a job. But he needed you just as much as you needed him.
6 seconds sound clip from the Creature from the Black Lagoon (1954) movie soundboard.
You can hear this line at 00:56:04.244 in the Blu-ray version of the movie.
Quote context
[...]
- Hunting calls, mostly. Animals out for the kill.
- Some of them are cries of fear, like people who whistle in the dark.
- I'm not exactly blind. You're worried about what's happened between Mark and David.
- Why not?
- If it weren't for Mark Williams, I wouldn't have my work or even a job.
- You've more than repaid him many times over.
- Why, a good part of his present position at the institute is due to your valuable research.
[...]