Quotes from book
The Pleasure of Finding Things Out
The Pleasure of Finding Things Out is a collection of short works from American physicist Richard Feynman, including interviews, speeches, lectures, and printed articles. Among these is his famous 1959 lecture "There's Plenty of Room at the Bottom", his report on the Space Shuttle Challenger disaster, and his speech on scientific integrity in which he coined the term "cargo cult science". The original foreword was written by Freeman Dyson.

“I have a limited intelligence and I've used it in a particular direction.”
" The Pleasure of Finding Things Out http://www.worldcat.org/wcpa/servlet/DCARead?standardNo=0738201081&standardNoType=1&excerpt=true", p. 2-3, transcript of BBC TV Horizon interview (1981): video http://www.youtube.com/watch?v=NEwUwWh5Xs4&t=2m53s
The Pleasure of Finding Things Out (1999)
Context: I've always been rather very one-sided about the science, and when I was younger, I concentrated almost all my effort on it. I didn't have time to learn, and I didn't have much patience for what's called the humanities; even though in the university there were humanities that you had to take, I tried my best to avoid somehow to learn anything and to work on it. It's only afterwards, when I've gotten older and more relaxed that I've spread out a little bit — I've learned to draw, and I read a little bit, but I'm really still a very one-sided person and don't know a great deal. I have a limited intelligence and I've used it in a particular direction.

Note to the mother of Marcus Chown, who had admired the profile of Feynman presented in the BBC TV Horizon program "The Pleasure of Finding Things Out" (1981). Written after Chown asked Feynman to write her a birthday note, hoping it would increase her interest in science.
Photo of note published in No Ordinary Genius: The Illustrated Richard Feynman (1996), by Christopher Sykes, p. 161.
In a " Quantum theory via 40-tonne trucks http://www.independent.co.uk/arts-entertainment/books/features/quantum-theory-via-40tonne-trucks-how-science-writing-became-popular-1866934.html", The Independent (17 January 2010), and in a audio interview on BBC 4 (September 2010), Chown recalled the note as: "Ignore your son's attempts to teach you physics. Physics is not the most important thing, love is."

Source: No Ordinary Genius (1994), p. 251-252, from interview in "The Pleasure of Finding Things Out" (1981): video http://www.youtube.com/watch?v=NEwUwWh5Xs4&t=45m21s
(Also in book The Pleasure of Finding Things Out (1999) p. 23.)
Context: People say to me, "Are you looking for the ultimate laws of physics?" No, I'm not. I'm just looking to find out more about the world and if it turns out there is a simple ultimate law which explains everything, so be it; that would be very nice to discover. If it turns out it's like an onion with millions of layers and we're just sick and tired of looking at the layers, then that's the way it is!… And therefore when we go to investigate we shouldn’t pre-decide what it is we are trying to do except to find out more about it… My interest in science is to simply find out more about the world.

It is not odd at all. You only think you know, as a matter of fact. And most of your actions are based on incomplete knowledge and you really don't know what it is all about, or what the purpose of the world is, or know a great deal of other things. It is possible to live and not know.
from lecture "What is and What Should be the Role of Scientific Culture in Modern Society", given at the Galileo Symposium in Italy (1964)
The Pleasure of Finding Things Out (1999)

I might think about it a little bit, and if I can't figure it out then I go on to something else. But I don't have to know an answer. I don't feel frightened by not knowing things, by being lost in the mysterious universe without having any purpose — which is the way it really is, as far as I can tell. Possibly. It doesn't frighten me.
Source: No Ordinary Genius (1994), p. 239, from interview in "The Pleasure of Finding Things Out" (1981): video http://www.youtube.com/watch?v=NEwUwWh5Xs4&t=48m10s