Each reader will draw different lessons from Mezzofanti's life. As a language enthusiasts, here are my conclusions:

• It is possible to learn languages on your own. You do not have to take classes or attend a University to speak a language fluently.
• You can learn a language from a variety of sources . Mezzofanti learned some languages from books, other from conversing with soldiers or students. I am quite sure he would have been a language tape buff but they did not exist at his time.
• You do not need to travel to distant lands to speak their languages perfectly. Mezzofanti never left Italy.All you need is access to good material and native speakers.

Of course Mezzofanti was an exceptional person and that the average student will not have the same achievements, but in my opinion what Mezzofanti achieved in big anybody can achieve in small.

Do not forget that Mezzofanti spent all his life studying languages. He never married and had time to study at night. He had ready access to probably the largest number of foreign language speakers in the world at the time. People from all over the world flocked to Rome to study Catholicism and Mezzofanti used that ressource to learn and practice a great many languages. So unless you are in the same position, it is only normal that you can learn less than Mezzofanti.