This is one of those books that I felt like everyone had read as a teenager except me, and I had no clue what it was even about.
You know, given the title and the fact that I'm familiar with the song that uses the same reference, I really ought to have known.
I have to admit that this was kind of blatantly fake for me from the get-go. I could tell it was not real, and the writing kind of bothered me, because it read not like a diary of a teenager, but like the diaries adults think teenagers keep, if you know what I mean.
The main character herself was a bit over-the-top as well. The whole addiction aspect of her story was a bit overplayed (it seriously took her one time to get so wildly addicted she dug a hole for herself?), but was probably more of an important thing to discuss at the time, given how long ago this book was written (okay, it's not ancient, but drugs were in a different place than they are now, certainly.)
It read a bit like one of those made-for-tv-specials I watched when I was very young about teenagers and drugs. There is an awful lot of space dedicated to the effects of the various drugs, all written much more clinically than it seems like a teenager actually addicted would manage, and comparatively little space dedicated to the more normal social aspect of her life, which is apparently a large chunk of what drives her to drugs.
In the end, I did enjoy it enough to read straight through it, and it is a quick, easy read with an interesting storyline. I didn't feel any less desire to do drugs after reading it, but given I've never felt one to begin with, your mileage may vary on that. It's perhaps worth picking up as a period piece, explaining what it is that was causing so much concern in adults of the 70's for those of us who were not there at the time, and as that it does succeed.