I can’t really figure out what made the difference but it might have been the fact that I used a different style onion. It sure doesn’t take much to change the flavor.
It also could be my taste buds as I am getting old enough that sometimes I just don’t taste things as well as I used to.
both things you suggest can be true. age changes taste b/c buds die off, smell receptors in your nose die off, plus brain changes over time can change flavors you enjoy. this happens in older animals too.