That's awfully simplistic, actually.
And wrong.
Whilst the premise of the show is indeed a high-school chemistry teacher faced with inoperable cancer decides to start making crystal meth, it isn't only to make some money. Walter has a personal crisis where life kicks him the balls just one time too many. He already has an unsatisfying life, one job that doesn't pay enough and a second he hates and a disabled son. There is no adventure in his life.
The cancer diagnosis is the catalyst for Walter to live a little. It is the push he needed to change him from going out with a whimper into going out with a bang. The crystal meth happens when Walter goes along for a ride with a relative in the police in a drug-lab bust and he realizes not only do they make a lot of money, but he knows that he actually has more than enough knowledge to make crystal meth himself. In fact, he can make it in superb quality.
It is more than an adrenaline rush for Walter: it makes life interesting, exciting, adventurous. And very dangerous.
And you can see all that just from watching the first episode.
Wade.
