I worked at a chair for 12 years - in that time I've seen a lot of PhD students go through this.

If it helps anything at all: It's normal. At this point, you've already proven you're smart and knowledgeable. Now, the universe wants to see if you can also finish what you've started. That's the main thing a PhD proves: That you can take an incredibly interesting topic and then do all the boring stuff that they need you to do to be formally compliant with arbitrary rules.

Focus on finishing. Reduce the scope as much as possible again. Down to your core message (or 3-4 core messages, I guess, for paper-based dissertations).

Listen to the feedback you get from your advisor.

You got this!

Switch back and forth between trying and reviewing. Often it can be good to just try before reviewing, to get your feet wet. Don't spend too much time. Then when reviewing you're going to understand it more. Repeat this process.

But there's some things to remember that are incredibly important

  - a paper doesn't *prove* something, it suggests it is *probably* right
    - under the conditions of the paper's settings, which aren't yours
  - just because someone had X outcome before doesn't mean you won't get Y outcome
  - those small details usually dominate success
    - sometimes a one liner seemingly throw away sentence is what you're missing
    - sometimes the authors don't know and the answer is 5 papers back that they've been building on
  - DO NOT TREAT PAPERS AS *ABSOLUTE* TRUTH
    - no one is *absolutely* right, everyone is *some* degree of wrong
  - other researchers are just like you, writing papers just like you
    - they also look back at their old papers and say "I'm glad I'm not that bad anymore"
  - a paper demonstrating your idea is a positive signal, you're thinking in the right direction

My choice is to not do a PhD and just invest as much or as little effort in the topic as you like

For me, it wasn't so much about mitigating this cycle as much as recognizing that the grit of pushing through that last 20-30% is actually a valuable life skill that the PhD could teach me to do, and that projects that I felt like I would never want to touch again actually started to become interesting again after I had left them for a year or so.

It seems almost inevitable...

Acknowledge it is normal? Attempt to buy deeper into the delusion ("Yeah my work is awesome and unique!"). Use stimulants to force enthusiastic days every once in awhile?

Find a brand new hire who wants to get tenure. Getting a PhD through in 4 years is catnip for tenure at most universities (stateside). We then dropped off my dissertation in the middle of NSF funding week. I paid for it during orals (4 hours), but they all signed within a few days without comment.

Uhh... unless you plan to stay in academia? Then, this is a terrible idea.