Events of this magnitude come around every 30 - 40 years. (ibankcoin.com)
No other event of this magnitude would ever be taken lightly, so don't feel guilty for treating this time in your life as the very big deal it is. (childdevelopmentinfo.com)
While events of this magnitude probably won't be occurring in 2012, we should be open to the fact that they might. (politics.co.uk)