Explanation on what can go wrong if Hooks were called inside loops or nested functions?

The Rules of Hooks section states that the first rule of Hooks is to only call hooks at the top level, i.e. "Don’t call Hooks inside loops, conditions, or nested functions". Later in the section, it explains what happens if we put a Hook call inside a condition. This still leaves me with some questions/doubts though. Are there examples where something can go wrong if Hooks were:

• called inside a loop?
• called inside a nested function? Furthermore, isn't a custom hook just a nested function? 🤔

I've tried to dig into some related questions on Stack Overflow here and here, but the answers provided only give the correct examples, but not the incorrect ones.

Could you provide incorrect examples for the other two cases? Or at least a little bit clarification would be most appreciated. :)

Rules of Hooks セクション、特に条件付きのHook呼び出しについての既存の説明から始めます。ループ内やネストした関数内でのHooksについて、誤った例または補足説明を追加し、custom Hooksがどのように異なるかも含めます。これらのケースがドキュメントで明確に説明されれば、作業完了とみなします。