Two examples: I always thought of myself as a morning person - I like getting up early and not staying up late, and I feel good when I wake up early. But I realised I am much more productive later in the day. It doesn't seem to be the number of hours after I wake up, it is about actually being later in the day. So I work better if I get up later and work later. Unfortunately I don't often get to do that, but I do when I can.
Next, I prefer my work space to be light and bright. But I actually work better in a pretty dim environment. I have to take regular breaks to get some natural light though, otherwise I just feel like I'm turning into a troll.
Just some random thoughts.