Jesus leaves the words with us so that after the resurrection their meaning shall become apparent. It is the same with us. After we have committed our lives to Jesus we shall begin to understand these things as they become more and more clear to us. We do not receive all the understanding at once; we could not make sense of it if we did. And here Jesus says the same thing, "the Spirit blows when and where it wills" bringing whatever we need at the time.
That is one of the wonders of the spiritual life, the way everything falls into place at the exact moment it has to. For us, all we have to do is consent to the work of the Spirit in our lives.