Part 1: So... I have my viva looming and I've done very little prep to date. Partly through procrastination, partly through the fact I work full time in a non-uni based job. But mostly because I just cannot bring myself to look at my thesis or think about my work.

Brief context: through the course of my PhD I had a number of internal supervisors and advisors, as well as external collaborators to whom I was accountable but who had no buy-in to my PhD. There was no single person who had an active advisory role for the entire period - it was all a bit piecemeal. I submitted a thesis on the last permissible day, knowing it was flawed, only having received feedback from one of my supervisors who joined the process 2/3rds of the way through and who is only a few years post-PhD himself. As far as I know my primary supervisor hasn't read it, or even the penultimate draft (which he did receive). It's over a year since I last had a proper conversation with my primary supervisor about my work.

My thesis was supposed to be on topic X in disease Y. I did a lot of reading about topic X, both broadly and in the context of disease Y. I know that literature very well. I did a lot of analytic work on it.... most of which did not end up in my thesis. This is because I never totally finished most of it as I spent large chunks of time working on various projects with external collaborators that my supervisor presented to me as opportunities. They were indeed opportunities, and I learnt a lot, but apart from all being in disease Y they do not hang together seamlessly as a body of work. It took a lot of effort to cobble together a post-hoc narrative around the work I did finish and include, and I realised very late on that my knowledge of the literature did not fully overlap with this narrative...

Part 2:
...so my introductory chapter (written near the end, at speed) is lean to say the least.

On top of the list of errors and omissions that I can come up with without even looking at the document, I feel very vulnerable going into the viva. Looking at sample viva questions, such as "Why did you do such and such? What would you do differently...?" my knee-jerk answers are somewhat on the bitter and cynical side. Though I felt incredibly relieved to hand the thesis in, I am not proud of it in any way. The work in each results chapter is defensible in its own right, but harder to defend as a whole (e.g. I took different approaches to particular things in different chapters, partly to keep collaborators happy). Essentially, if I walked into the room and my examiners said: "Your thesis is rubbish" I'd probably shrug and say "You're probably right" rather than putting up a fight.

I don't have much time available between now and the viva to prepare. Does anyone have any words of wisdom as to what I should do? Particularly with regard to how to look more positively at it. Someone pointed out to me that "You don't have to like your thesis, you just have to live with it." At the moment I'm not even feeling that - how do I talk myself around to a position where I can at least live with it?

Ok you've spent a lot of your life on this PhD. Do you want that to count for nothing? Because if you can't prepare to defend yourself in your viva you may be walking into failure. That's assuming your examiners are unkind / very critical. You may be more lucky.

The first thing you need to do is take ownership of your PhD. It is YOUR PhD, not your supervisors'. Yes you had supervisory issues, but it is ultimately down to you how things turned out. And you are the one who has to defend it. This may be a bit painful, but you need to face up to the fact that it's your thesis, and it's your responsibility.

You've probably seen Bilbo's 5 viva tips posted here before. These are the 5 things I think anyone can benefit from thinking about before a viva. And this preparation can be done quickly. They are: originality of my thesis, contribution to knowledge, methodology, weaknesses/gaps/mistakes, and what would I do differently if starting again.

Yes I do recommend looking at mistakes, and what you might do differently, but not to the extent you're doing. You need to think more about positive aspects of your PhD. Where does it add to knowledge? What's different about it? And how did you approach do this?

Ideally this must be thought of at the higher level, across the whole thesis, but you can tackle this at the level of individual chapters.

I suspect the examiners may want you to rework your intro and conclusions, so you could think about how you would improve those yourself. But don't offer to do it unless they actually ask you to.

Good luck! This preparation can be done in very little time. I was a part-time PhD student managing near the end on no more than 5 hours study total a week, usually in 1 hour chunks spread throughout the week. But viva preparation need not take ages. Don't let yourself down by not doing it.

It's a bit like doing a job you don't have a passion for. Sometimes you just have to get things done.

It sounds like your choice is between defending the viva half-heartedly and perform poorly, or defending as best as you can and getting a pass and moving on. Out of the two I would advise someone to choose the latter.