This. The best I've ever achieved is maybe 15 puzzles on one year, with gaps for the days I missed. And this was when the puzzles were incrementally building upon implementing a bytecode interpreter, which was relatively little work per day.

Once I miss my first day, playing catch up is an effort in vain, as the puzzles start taking 4+ hours to solve each, solving multiple in one day is a full-time commitment.

Most advents of code I've fallen off sharply after day 7-10, if not sooner, and I'm pretty sure I'm not alone in this. I think this is a welcome change.