We know how to recite a prayer, but that is a far cry from praying. If we recognize the realm of that expression, we will gradually learn to pray.
Prayer is an expression of people.
To lead in prayer, he needs to know the people well enough to answer that question. They can hardly say amen to what is not their prayer. Thus, it is hard for anyone to direct a crowd of strangers in prayer. Such prayer would begin with an assumption, proceed in generalities, and be deficient, in expressing the people's urgent yearning. This expression of people must be in understandable words.