One of Proust's peculiarities is that he frequently alludes to experiences he is familiar with, but declines to comment on them, except in the most obscure way. He may relentlessly relate every word uttered by every upper-class French twit at a dinner party, while dismissing a duel he fought with a dependent clause, or the twelve years spent in a sanitarium with a single paragraph. And so he tantalizes us with the drug experiences, undertaken, of course, for reasons of health, that he obviously enjoys tremendously...
"Not far thence is the secret garden in which the different kinds of sleep, so different from one another, induced by datura, by Indian hemp, by the multiple extracts of ether-- the sleep of belladonna, of opium, of valerian-- grow like unknown flowers whose petals remain closed until the day when the predestined stranger comes to open them with a touch and to liberate for long hours the aroma of their peculiar dreams for the delectation of an amazed and spellbound being."
-"The Guermantes Way"
"When one absorbs a new drug, entirely different in composition, it is always with a delicious expectancy of the unknown. One's heart beats as at a first assignation."
-"The Captive"
"It is easy to speak of the beauty of opium..."
-"The Captive"
Given these random comments, it is not difficult to surmise what Proust might have found amusing had he lived in these times.