It is simplistic, but to answer your question fully would be a book length answer.
Revolutions are very viral. Once you give people a taste of something, the pent-up anger built elsewhere would explode with unpredictable consequences.
Why bother asking when you know the answer but simply don't like it? Any question that starts with a rejection fails totally. "How did humans get to be so intelligent, but don't tell me none of that Evolution stuff. I won't believe it." Do some research, read any of the books on the lives of the people then. Saying "I just don't buy it though" is basically saying, "The only thing I will believe is any answer but the truth; especially one that confirms my biases."
His self-immolation moved Tunisia and it instantiated the Tunisian revolution. It worked there as the tyranny was toppled and everyone is happy. But, the revolution didn't end there. In no time, it toppled Egypt, making the country restless since then. Then it toppled Libya, still going through a civil war. And then, Lebanon, Jordan, Yemen, Syria, Iraq, Oman, Kuwait and so on.
Some of the changes resulted were good. But, it also indirectly brought the ISIS and other headaches.
This has always been the trouble with the revolutions. Especially if you are in a position of power, revolutions can be very, very disconcerting. French revolution changed Europe significantly. It also influenced the Russian revolution that had even bigger impact inspiring things as far as Cuba and China. Eastern Europe and Central Asia changed like nothing else. In the same way, American war of independence and Indian independence movements inspired scores of nations gaining their own.