I've only been coding professionally for a few years and I've too noticed dramatic productivity differences some days compared to others that aren't related to unexpected technical aspects ... it's just the volume, speed, accuracy of my coding all by itself it seems.
With something that takes a lot of focus I think mental state is absolutely huge.
We see athletes go through warmups and traditions before they start a game to get going not just physically but mentally ... makes me wonder if I should do the same.
Personally, it's much easier for me to be invested in a task when what I'm doing is 'interesting' to me.
Almost always and ironically, when something's interesting to me it's usually more difficult work and thus, contains far more unknowns, hence making estimates that much less reliable.
With something that takes a lot of focus I think mental state is absolutely huge.
We see athletes go through warmups and traditions before they start a game to get going not just physically but mentally ... makes me wonder if I should do the same.