Don't bother bringing real-world examples to FT Verse. Zeref practiced life-death magic and he was cursed for that. If Zeref learned that curse on his own. He wouldn't have bothered saying God Ankeseram Cursed him as simple as that. Zeref curse is not something that he learned on his own.
who cursed him? Manga/anime did not show anyone cursed him.
He was pissed by his tutor - "you brother never back alive... you will be expelled". His mentally state was broken and it triggers his curse.
I previously so m. times said "how you are able to be so unwise".. well. i need to say it again.
Zeref NEVER learnt this curse. Zeref learnt Life and Death magic. Which was called as "forbidden".
As result of his learning (abuse Life and Death magic) with addition of his mentally state as its trigger, he got that he got.
It's easy suggest that its mechanics same with process of turning DS into dragons.
On other hand, canon did show any indication that anyone used anything on him (curse him), as well as with Mavis case (she got curse after abusing INCOMPLETE Fairy Law).
Macarov and Laxus who used "safe version of Fairy Law" did not get Ankseram curse.
P.S. Why Zeref should make "new name" ? He's 400+ yo. In his era ppl worshipped Ankseram, so he simply call it Ankseram wraith/curse.
P.S. (2) You still did not link any proves for your previous statement
