As Flamingo said patience. I would add in that today we can also pick up quite a bit of chemistry which explains flavors or in your grandpas generation lots of trial and error skilled in the art understanding tastes.
@GVV - Welcome to WMT! I haven't lived there in a long time, but I grew up near Buffalo and went to high school on Grand Island, not too far from Niagara Falls. Your story is a very good one. I started making wine a couple years ago and joined this forum shortly after. The folks here are extremely helpful and forthcoming with information, a lot of which they've learned the hard way. Good luck!