> Besides, building a LLM _truly_ from the scratch, just using the famous 2017 paper and numpy manuals is not fun at all, esp. for a high schooler.

To you it isn't, is my entire point here. But why extrapolate what you think is fun, to others? Sure, I don't find that fun either (although useful), but who am I to say it isn't fun for others?

We can continue this pointless conversation, in the tone "who you are to tell what is fun to others and whst is not". You'd be impervious to any argument stating that dealing with far beyound someone understanding and requiring countless hours of digging into difficult math is not fun even for those who thinks it should be fun, as they presumably, loves everything STEM.