I quit smoking cigarettest last year. It wasn't easy and there are still occasional cravings but I think it'd be a lot harder if I believed it was some sort of disease I had no power over. I didn't need some cult-like support group and I certainly did not need some fictional sky fairy. I don't see how nicotine is any different than any other drug other than it's commonly accepted that one can simply "quit" which makes it a lot easier. If you're told by everybody you can't do it on your own, you probably won't try hard enough to prove them wrong, considering you'll see continuing to struggle as a futile endeavor.
I believe what you're teacher is looking for, tho, is some sort of admission that the believe that drug addiction is caused by a lack of willpower leads one to deny it as a disease. I'm not sure willpower is really the right word, tho. People always have the power to exercise free will and make choices. When you want a drug more you care about the consequences consequences, you choose the drug. It's less a matter of willpower and more a matter of what's a priority to you. Some people are selfish as none-ya puts it and choose drugs over, for example, feeding their kids. That's a choice. Blaming the drug is an excuse that makes the ugly truth more palatable to people. It's much easier to believe drugs force people do bad things than it is to believe average people are capable of horrific things for any number of motives -- with any number of sufficient temptations, whether that be drugs or whatever. It's certainly true that certain drugs can become a sufficient temptation for a person to not want to choose to abstain, but there is still a choice.
