That has been the argument I have used with myself and colleagues, and everyone nods their head in agreement. Work tasks, emails etc can be done in the gaps but the PhD is special. Right?
I looked at my diary for the week, and now I have picked up a lot more work (great for the bank balance), I have meetings dotted throughout and I thought, shit how am I going to advance the PhD without having to work in the wee small hours. Then I challenged myself about the time issue and thought why can't I do focussed one hour sessions. Tiger Woods (for all his faults) said sometimes his best practice sessions are after only twenty swings and he happily calls it a day.
So yesterday I tried it and it worked. A one hour session, focussed and I got heaps done and at the end it felt great. I broke the mental block that I had built and had been made concrete through all those conversations.
I encourage you to give it a go. Don't write that hour off at the end of the day, take a deep breath and dive in like you had eight hours free in front of you.
As a CEO I worked with once said, 'it's often a mindset change that is required...