Rav Shlomo Mann made an interesting observation about the Tenth Plague. For the first time. Hashem refers to the plague as a נגע, NEGAH, instead of the usual word for plague, מכה, MAKA.
Rav Mann continued by explaining that the word, NEGAH, also means לנגוע, to touch. The other nine plagues affected the Nile River, the cattle, and the people. None of them actually touched Pharoah, until the Tenth Plague hit. He was a first born himself, and it drove home the point, that he could have been killed, as well.
This is a serious lesson about human nature. We might hear about problems and suffering all around us. But we may not fully understand what others are going through, until we go through it ourselves.
When Pharoah saw first hand the devastation of the death of the first born, which included his own son, he was finally moved. He then agreed to let the Jewish people go.
This is what G-d told Moshe. He said this last plague will touch Pharoah personally. He will finally realize that he has no choice but to stop the devastation, and listen to Moshe.
We should learn from this that we should wake up and act as we should, before we get hit over the head, to make us realize the proper way to conduct ourselves in our interaction, with G-d and man.