Questions from 21-st century's Milinda The Lotus Sutra’s parable of the burning house imagines inhabitants of a house in fire. They do not register the dangerous situation and therefore  “the thought of getting out does not occur to them”.
Later on, the Lotus Sutra ascribes the following comment to Buddha: “Even there, in that threefold universe that is like a burning house, they enjoy themselves and run about. For though they are being afflicted by a great deal of suffering, the thought that they are suffering does not occur to them.”

I imagine a 21-st century Milinda brought up in critical thinking. He is alike to the elder Milinda in his attitude of questioning, but - different from him – today’s Milinda is not willing to accept a bunch of metaphors as a sufficent answer.

21-st century Milinda has no remembrance of past lifes. He does not expect a future life. In addition, he has learned to accept: Present life is not arranged to primarily satisfy human wishes. He asks his modern "Nagasena":


If I do not suffer from rebirth: Why worry about rebirth?
If I do not remember any actions in past lifes: Why worry about karma?
If I expect that death - quite naturally - ends the life of all beings: Why worry about nirvana?
I distinguish between questions with answer and questions without: Why strive for enlightenment due to meditation?
I'd hazard a guess that if the Ven. Nagasena were around today he might respond with something as follows:

1) Just because you don't know that you have a problem doesn't mean there isn't one.

2) One cannot conclude that something in the past didn't happen just because you don't remember it. For example, I don't have any memories of being an infant or being born but that doesn't mean that I never was.

3) One should be concerned about Nirvana because it is not some sort of prize after death, but a reality that is fully realizable in the here and now.

4) One should strive for enlightenment through meditation because meditation is a necessary part of the spiritual practice. Without it one cannot expect to attain anything.