First of all let me say that my questions are not meant as attacks on Casey or the community.
I discovered the project a few months ago, and started following recently. In the first few videos Casey mentioned something that this project may take 2 years or so. I'm not holding his word against him or anything. I believe he didn't plan/know how long it'd take. So this brings me to the following questions:
Besides Simon's points, the actual "programming" on Handmade Hero is not that long. Most videos, on average, are about 2 hours long, and with 667 videos, it comes out at around 1334 hours. If you work full time (8 hours a day, 5 days a week, for a total of 40 hours per week), then it's only been around 33-34 weeks (just a little more than half a year). Not considering that most of the time is for explaining and "blackboard" videos, or streaming in 2 hours chunk usually breaks the flow.
That's pretty accurate estimate. Exact length of regular "handmade day xyz" videos is almost 1262 hours. This is excluding any chat, ray, and prestream video time. So that is ~31.5 full-time work weeks.