If you're walking along and someone tags you and says 'You're it!' and you don't bother to tag anyone else (indifference), how long exactly will you be 'it'?
You're only 'it' if you're playing tag. The power to be 'it' has no leverage on the non-player
One full hour
A calendar year
You're 'it' for the rest of your normal life. The curse will follow you through decades, continents and different careers
It extends beyond your own lifetime. Your children will bear the burden of being 'it'