Does using large libraries inherently make slower code?

Question

I have a psychological tic which makes me reluctant to use large libraries (like GLib or Boost) in lower-level languages like C and C++. In my mind, I think:

Answer 1

Excess code doesn't magically make the processor run slower. All it does is sit there occupying a little bit of memory.

If you're statically linking and your linker is at all reasonable, then it will only include the functions that you actually use anyway.