"Why didn't find find my file?" I wondered sometimes. "I know it's there!"
More often than not, I'd forgotten to use -print. Without -print (or -ls, on versions of find that have it), find may not print any pathnames. [This is probably the feature that confuses and "turns off" more beginning find users than any other. -TOR ] Some versions of find will output an error message or add the missing - print for you - but you shouldn't expect it.