Wondering what the elder said

I often see from weblog that people often use the present tense for what their elders told them even most of the time their elders are already dead. For example


(Fact: All the grandpas in the following cases are dead.)
a) My old grandpa used to tell me that when a friend who has always stood with you when times are tough tells you that you are wrong, you should listen to them.

b) My grandpa used to tell me that the best and easiest way to play major league baseball is to be a catcher.

c) My grandpa used to tell me that when you get a chill down your spine for no reason ,it's because a loved one that has passed has come back to see you.

I simply don't understand why the present tense can be used in the above cases. Shouldn't we use past tense or put a pair of double quotation mark to show that 'this was what my grandpa told me'? Following are my thought...
Total past) My grandpa told me that when you got a chill down your spine for no reason, it was because a loved one that had passed had come back to see you.
Double Quote) My grandpa told me that "when you get a chill down your spine for no reason ,it's because a loved one that has passed has come back to see you".

I think if you treat what other poeple told you in reported speech, you should at least put in the double quotation mark. However most of the time I don't see quatation mark used in weblog. I simply don't understand why the present tense can be used. Is that because the speakers believe what their grandpa told them are truth and that's why they use present tense for what their grandpa said?