When people ask 'What do you want to do?', I want to ask them, is the question about 'me' or the question about the 'action'. Typically, this question actually means, 'What is it that you are going to do to make your life better? (monetarily, status, security etc)'. This is what I meant by the question being about 'me'. Then there is the other variation which is about the 'action'. The correctly worded question for this variation would be, 'What is it that you love so much that you would do it forever irrespective of other considerations like money, status etc?'.
So, for me to answer the original question, 'What do you want to do?', Ill have to split it into these two variations and then address the variation that the person is interested. Typically, people either do not have time/interest to discuss this or do not have an intellect that is sharp enough to cut through the mindset that posed the original question, and such people mostly only mean the first variation. I do not want to answer this question without making the point about the two variations and hence the failure to communicate.
The answer for the first variant would be that my life is as good as it can ever be and it can never change. I have no future, in terms of career, growth, status, and hence there is no need to worry about them. Security (in terms of food, health etc) is an issue but these are quite trivially taken care of. The answer for the second variation is that I would like to find out what is the best and holistic way I can contribute to the society (NOTE: please do not understand this as 'social service') and then spend the time I have doing that. If there is no group of people doing what appears to be the correct way to me, Ill go and do it. If there is such a group and if it appears to me that my time is best utilized by joining them, Ill join them in whatever capacity I am capable of (be it a manager or a security guard) and assist them.