I planted over 100 sunflower seeds behind my vegegable garden this spring. Only 17 or so germinated. It might have been that year-old seed I used or some anti-germinating weather phenomenon. Next year, I'll start them in trays inside. I want a little slice of Italy back there. A few years ago, we visited Tuscany and saw acres of sunflower fields... happiness and cheer as far as the eye could see.
So here is a little happiness for you... no side effects... no unpleasant aftertaste.