When I was in my late teens and early 20s - in common with a lot of people that age, I sampled a broad variety of drugs. I particularly liked downers. I have a very hyperactive mind and they would often settle me to the point where I could form clear trains of thought without interrupting myself.
I also found Speed to be very good for studying as it focused my concentration; however the physical side effects were not pleasant. Amphetamines will wear your body down faster than anything.
I never knowingly took ecstasy although sometimes it's difficult to tell what you're getting. I certainly have never taken cocaine. I associate it with a certain type of person - It's the drug of choice for the metropolitan, upper middle classes. Aside for blowing-up the user’s ego to epic proportions the drug doesn’t appear to have any positive effects.
Hallucinogens were like rollercoasters that kept getting faster and faster. You would think you’d reached a peak and then it would just keep building in intensity. It’s a strangely addictive sensation. I didn’t take all that many serious trips, but I remember them all and I still have flashbacks.
My last serious drug episode occurred in the months following my Grandmother’s death when I methodically worked my way though a substantial supply of morphine that had been building up in her bedside drawer.
These days I smoke pot a couple of times a month, chew Qat on the rare occasions I can find it and I take mushrooms three or four times a year. I like mushrooms a lot; they make you realise how much you routinely take for granted. You couldn’t function in that state all the time. You would spend you life open-eyed in absolute wonder at how god damn beautiful the world is and nothing would ever get done. It’s a nice mental space to dip your toes into every now and then but you have to treat it with respect.