Why didn't he just write his own name in the book followed

because thats not how it worked

Because you can't.

>>153224070
Not OP, but why not? He tested out the Death Note using very elaborate means and found out the only limits are logical and physical (for example, an inmate in a Japanese prison can't die in front of the Eiffel Tower, but if he commanded a free man to do the same he could easily book a flight there only to die). It's entirely possible that he could dictate the time and conditions of his own death as long as it doesn't defy logic (like "never dies" or "dies in 4023) or isn't physically impossible (like "dies on the moon").

>>153224027
>Why didn't he just write his own name in the book followed by "dies in his sleep on his 100th birthday after having never been arrested or identified as Kira"?

And then he gets hit by a bus the next day, spends the intervening decades paralyzed in a nursing home, finally choking to death on his own sputum on his 100th birthday.

In his sleep and having never been identified as Kira, of course.

File: Rules_XXVII.jpg (97KB, 634x1024px)

97KB, 634x1024px

>>153224027
>>153224362

>>153224027
Even if you were to make out a proper method of death, the Death Note can't manipulate everyone else's actions dependently of the victim. Just because you write "never having been arrested..." doesn't mean that every human on Earth will be somehow influenced to not do so.