I did my first degree at [Very Prominent UK University], and in those days ([the early 1980s]) [VPUU] was one of the few Universities that did a 4-year Bachelor's course, of which the last year was a research year, culminating in a thesis, which was regarded by other universities as equivalent to a Master's. I had done very badly in my final exams, and was on the borderline between a second and a third class degree on the basis of my exam results (my P-Chem let me down, but I had done well in my Organic and Inorganic exams. Ironic, because I really enjoyed spectroscopy, thermodynamics and quantum chem. Oh well!).
I realized that I needed to work really hard in my fourth year if I was to have any chance of coming out with a second and going on to do a Ph.D. I was very fortunate in my Research Instructor. He was a new recruit, and keen to make a name for himself at [VPUU]. I got an interesting synthesis project to work on, trying to make the carbon skeleton of [well-known natural product class], and I put as much time in at the lab as I could. I got on well with my supervisor, and he advised me to apply to various universities to do a Ph.D. in Organic synthesis.
I applied to many universities, and was rejected by all but one ([another UK university],my supervisor's alma mater). I got in there, to work on a project sponsored by [Famous Pharma Company]. I did a summer internship at [FPC], and started work at [UK university] in September [redacted], working on the [project P] until [late 1987.]
Sadly, I became very disillusioned with my Ph.D project, and almost quit. I managed to piss my [FPC] supervisors off so much they withheld my grant money for my last term. My supervisor, a really nice guy who had been very tolerant, told me that in all honesty he couldn't recommend me for a post-doc as I was too unreliable (ie I spent too much time in the pub and not enough in the lab).
My parents persuaded me to come home and write up my thesis, which took me a year, spending about 4 hrs a day (I was so fed up with the whole thing that was as much as I could manage). At that stage I never wanted to do any research work again, so I decided to do a PGCE (a bit like an education diploma) and tried teaching High School chemistry for a year. I hated that too, so in 1991 I got an entry-level job (for a Ph.D chemist) in the chemical industry at [UK fine chemical company].
And the rest is history. I'm glad I stuck it out. But I had certain advantages that many of the people who posted their stories did not. My project was well-defined, if dull. The data I collected on the various substituent and protecting group effects was all valid data, so it went into my (rather short) thesis. My supervisor was very tolerant, and did everything he could to make sure I got my Ph.D. And I worked with a friendly group of people (which was part of the reason I spent so much time in the pub).
So I guess you could file this under "why I almost quit Grad School but didn't". I'm glad I didn't. My Ph.D. eventually allowed me to get a pretty well-paid job in the US, and allowed my wife and me to enjoy a much higher standard of living than we would have had in the UK.Thanks to PF for their story.