If you have gray hair in your beard, I don’t ask “why?” when you say something. Grandparents have seen some stuff and their life experience informs decisions and their thought processes in a way that gives them wisdom that youth (younger than 50, but especially younger than 30) simply does not have.
If you have gray hair in your beard, I’ll hold your word in high esteem merely because of that.
As a side note, all food made by grandparents should be good. Other than living, old people have done a lot of cooking. Just like life has informed their thought processes, so it has done to their cooking abilities. It's easier to taste the good in food than in advice (particularly when that advice requires action from you).