The most important theme in the novel was the experiment that Griffin, the invisible man, was working and it was not going exactly as planned. The way that the experiment went bad was not by accident; instead it was Griffin who had made the mistake of turning himself invisible. The reason that the invisible man had for becoming invisible was that he was suspected as to be a vivesectionalist and he did not want to be punished for it.
The reason for the final decision of becoming invisible was that Griffin thought there were many advantages. He finds out after becoming invisible that the whole thing was not thought through enough and being invisible had many more disadvantages than what he was expecting. This was an example of Griffin acting upon something before adding up all of the consequences of his actions. If he would have thought the process through Griffin would have, at least, made things invisible so he could use them and still be disguised. For instance he could have made some clothes invisible and even some common supplies that could have been handy along his travels.
Griffin did not realize how many disadvantages his invisibility had until it was too late. After becoming invisible Griffin realized that he could not sneak around people very easy and people still knew he was around even though they could not see him. The people could see his footprints and see him if he became dirty. Another thing that Griffin did not realize before his experiment back fired was that he could not eat if he wanted to stay invisible. The people around him could see the food inside his stomach, until his body absorbed it.