I've known the term "Zero Inbox" for quite some time, and without really intending to do so, I used to follow that idea. Only recently I found myself flooded with email in my inbox, some of it sent by myself, and I really felt confused. What am I supposed to do now? With what shall I begin?
This can become quite a burden, until everything is back in order. E.g. This blog post was in my head for about two months, but only now I got to the draft I sent myself.
Conclusion: overwhelmed inbox reduces productivity.
I don't really understand in human physiology, but I noticed something strange about myself: I'm used to sleep between 7-8 hours at night, and this keeps my highly active during the entire day. But it really does depend on when these sleeping hours begin: the earlier, the better. This means sleeping between 00:00-08:00 feels much better than sleeping between 02:00-10:00.
Conclusion: sleeping 8 hours doesn't guarantee productivity. It is only a requirement.
I wish I had worked at Fog Creek, just because they have amazing office space. Instead, my workspace is a cubicle. I know for a fact it is bigger and better equipped than other cubicles out there, but still it holds most of the disadvantages of cubicles. It's like software companies aren't aware to the fact programmers productivity is directly affected by their ability to concentrate for long periods of time.
Different tasks and different moods require different music. Each task has its own music which helps getting into the zone. This is why I have various different genres in my deezer playlists. Music is one tool to solve issues caused due to working in cubicles.
Many things has effect on our productivity, and it is difficult to manage them all. Sometimes we're more productive than in other times, but it is always impotant to be aware of that, and they to improve.