In formal debate, you need to define terms. Define ‘we’ as people with your national identity and ‘yesterday’ as way in the past (50-100 years ago). Then consider how the people of today are exposed to many more influences and how new lessons have to be learned. Celebrities set a new low standard, which opens up new lessons to be learned (which are really the old lessons). Technology has opened up new cans of worms. Gender issues have been in the news. The effects of bullying have new consequences. A lot of the old lessons (playing fair, trying one’s hardest, honesty, work ethic, cloning, stem cell issues, etc) have to be relearned in a new context. The old lessons need to be tweaked. That may give you a start. You may have to make it seem like the older lessons are really new lessons, which requires some verbal skill. I am not sure I did this justice, but maybe it’s a start. Good luck.