the.com/enemy
The person you'd most like to be right about, and most hate proving it.
means Someone actively opposed to you, working against your interests or wishing you harm.
from From Latin inimicus, literally un-friend (in- not + amicus friend) — the original opposite of a buddy, ancient Rome's version of the unfollow.
Free upgradeDoubt becomes the enemy without anyone declaring war.
Plural problemEnemies multiply faster than friends, requiring less maintenance.
Old idiomTime, perfection, and self all qualify as enemies.