We complain about the conditions of the desert; the lack of water; the shortage of meat; the taste of the miraculous Mahn. Even Miriam & Ahron get into the act when they complain to Moshe about his neglecting his wife Tzipora. We find fault with everyone & everything.
One of the most ancient, & certainly one of the most beautiful prayers in the Jewish liturgy is the Birkat Kohanim. In just 15 words, Hashem - via the Kohanim - promises us knowledge, wealth, security, Peace & an eternal relationship with Him. What more could anyone ask for?