Cousin's and their Siblings. Can you keep track of them?

Having written about our first cousins, our Aunt's and Uncle's children, I am in dire shape for their children.  How well do you keep track of the downline?

Since our trees are not to show them time has erased some of my mental data because I have not been near many of these people for at least 5 years or even much longer.

Being able to say that Bob M had 3 children.  What children did they have, where do they live.?
I suspect that in ten years our ability to get data will be less than today.  So if any one picks up where I leave off, where will they find data.

Libraries pulled the new and old phone books.  Libraries pulled many Encyclopedia's saying people can dig on the internet. All so sad.  Wish now I had kept my 50 + year old set of Encyclopedia's.
Like words have changed and meanings have been twisted.  It will be even more difficult for the future generations to track our families.

As close as we have been I have very little information on most of the first cousins families.

On Mom's side I have met all of the children of my Aunt's and Uncles.  But some was nigh on to 50 years ago and some as recent as 1 year ago.

Dad's side is not quite the same since the military was involved.   I think I got an hour with some of my cousins on my one Aunt's side.  She had five children. I got to know 1 via my Dad and yes she talked about them a lot but for contact, last time was in Dad's back yard while they were stationed in Monterey and we were in NAS Lemoore.   My other Aunt's children I know and have met their children and we communicate often.  Reverse of what it was like when younger.  My Uncle's children I have met. Except Robin I have not seen since she was two because she was taken away and family fought for years to locate and bring her back.  Her Dad has not seen her since about a year after my last seeing her setting in her highchair.

Seems all families have their problems.

Having tried to post the names and keep track and then if you share your stuck.  In fact one tree does not post our children or myself.

So Randy Seaver was saying how far back can you track, I am asking how far down below yourself can you track accurately of your family?  Your generation of family, all first cousins information to share someday?