When you put yourself into building something, days can fly by even as the years seem to pass quickly.
The days are long, but the years are short.
When you put yourself into building something, the days can go by in a dash. You get absorbed in the work, solve what is in front of you, and suddenly another stretch of time has passed.
It is a satisfying feeling, but also a reminder to look up now and then. The work matters, and so does noticing the life moving around it.