Early AoC was fun, you could get away without anything fancy until late in the game. Then it got harder, not fun, so I gave up and stopped touching it.

I didn't get very far into AoC this year as I ran out of time. Maybe I'll pick it up again later.

But my point is, I was surprised at how hard day 5, part 2 was. I didn't give up and solved it, but went away wondering whey I'd missed something obvious and overcomplicated it. So it brings some relief to know it was 'supposed" to be a bit challenging!

This was just my personal experience (which certainly came from trying out a different language than I typically use in my day to day), but I'd argue that day 1 part 2 wasn't _hard_, but improperly specified from the prompt. The examples given are:

  two1nine
  eightwothree
  abcone2threexyz
  xtwone3four
  4nineeightseven2
  zoneight234
  7pqrstsixteen

There is one critical example missing from this set and you can't exactly just figure out how you're meant to substitute the values without an example like:

  oneight

Thanks for the details. To add to this discussion, I have a script to see the progression over the days.

Looking at the last two columns, you can see how brutal 2023 was compared to 2022. Especially in the beginning. The first few days, most people keep playing, with a retention higher than 80% most days, and virtually everyone people solve both parts. In contrast, only 76% of people solved part 2 after solving part 1. And many people gave up on days 3 and 5.

Interestingly, the last few days are not that much lower. And that can be explained by the fact that AoC 2023 is more recent than AoC 2022, like you said. My interpretation is that this group of people will get over all the challenges regardless of the difficulty (to an extent, of course), while many other people will give up when they realize it will take too much of their time.

    Stats for year 2022 of Advent of Code
    -------------------------------------
    
    Day   Both puzzles   One puzzle       Total   Rel. puzzle 1/2   Rel. day before
      1        280,838       15,047     295,885              95 %             100 %
      2        232,752       12,403     245,155              95 %              83 %
      3        200,016       11,392     211,408              95 %              86 %
      4        184,435        3,734     188,169              98 %              92 %
      5        157,392        3,116     160,508              98 %              85 %
      6        155,921        1,602     157,523              99 %              99 %
      7        113,241        2,592     115,833              98 %              73 %
      8        107,224        7,659     114,883              93 %              95 %
      9         82,414       11,449      93,863              88 %              77 %
     10         85,075        5,511      90,586              94 %             103 %
     11         68,838        9,258      78,096              88 %              81 %
     12         59,253        1,061      60,314              98 %              86 %
     13         51,512        1,220      52,732              98 %              87 %
     14         49,051          991      50,042              98 %              95 %
     15         39,677        5,773      45,450              87 %              81 %
     16         23,298        5,650      28,948              80 %              59 %
     17         21,525        6,237      27,762              78 %              92 %
     18         25,420        4,927      30,347              84 %             118 %
     19         17,516          928      18,444              95 %              69 %
     20         22,141        1,003      23,144              96 %             126 %
     21         23,022        3,060      26,082              88 %             104 %
     22         15,393        5,083      20,476              75 %              67 %
     23         18,531          254      18,785              99 %             120 %
     24         16,419          252      16,671              98 %              89 %
     25         13,192        7,473      20,665              64 %              80 %
    ~/src/advent-of-code% ./stats.py 2023
    Stats for year 2023 of Advent of Code
    -------------------------------------
    
    Day   Both puzzles   One puzzle       Total   Rel. puzzle 1/2   Rel. day before
      1        230,737       73,941     304,678              76 %             100 %
      2        196,352        9,256     205,608              95 %              85 %
      3        130,406       19,913     150,319              87 %              66 %
      4        130,271       17,691     147,962              88 %             100 %
      5         80,255       31,029     111,284              72 %              62 %
      6        103,358        1,918     105,276              98 %             129 %
      7         81,905        7,308      89,213              92 %              79 %
      8         74,034       14,707      88,741              83 %              90 %
      9         76,438        1,229      77,667              98 %             103 %
     10         48,313       17,054      65,367              74 %              63 %
     11         57,339        2,386      59,725              96 %             119 %
     12         30,985       14,440      45,425              68 %              54 %
     13         38,217        5,223      43,440              88 %             123 %
     14         36,500        7,457      43,957              83 %              96 %
     15         40,881        4,156      45,037              91 %             112 %
     16         35,347        1,023      36,370              97 %              86 %
     17         24,014        1,097      25,111              96 %              68 %
     18         24,799        4,937      29,736              83 %             103 %
     19         22,525        7,197      29,722              76 %              91 %
     20         18,287        4,398      22,685              81 %              81 %
     21         14,311       10,149      24,460              59 %              78 %
     22         15,830          988      16,818              94 %             111 %
     23         14,562        2,964      17,526              83 %              92 %
     24         11,864        4,918      16,782              71 %              81 %
     25         10,522        3,048      13,570              78 %              89 %