yes, i think it's only in usa (ok maybe canada too) that 18 year olds are forced to get a 'date' in order to go to a social event. i really don't think that is healthy at all.
in the free world, people are allowed to go to social events on their own.
in the uk there is no high school 'graduation' (we only use that term for post graduate diplomas, university degrees etc).
but i think if someone does not want to go, they should not be forced to go.
i mean, you are forced to attend school all your life, and if you don't like it, why have social pressure to go back for one more time when you are still celebrating your escape?
(i had BIG social problems at school)
i left school after the age 16 exams (it is allowed in my country) and i still remember the last day, counting down the minutes as we sat on a hard floor, listening to the headmaster say something for an hour (i have no idea what he said, i was a fairly good student usually, but i knew nothing would happen if i ignored him for once!)
i went on to further education in a college that accepted young adults (16-18) plus older people who were resitting exams or doing diplomas.
i would have gone to the last day there (not really a full ceremony) as i really loved the teaching and the people there (finally had friends who did not laugh at me), but i was too busy at university (the celebration event was already at the start of the next year).
however i missed my university graduation as i was meeting my father in law for the first time in romania (long story) but i was glad for an excuse to be honest.
i didn't bother with any work related postgraduate ceremonies after that, as i don't really like having big crowds of people look at me. also you are supposed to hire the ugly black gown (there is truly nothing available that really fits small people despite what the larger people insist about 'one size fits all') which is really expensive, and then you have to go and eat somewhere really expensive, and it's all just too much hard work.
so, don't worry about missing graduations. there are more important things in life, like finding God, being a good friend to people and personally thanking those teachers who have made a difference in your life.