If you are the one who likes drawing family trees, tracing back your forefathers, here is some food for thought.
If you somehow manage to draw your tree spanning 800 generations, you will have effectively covered more than 50,000 years.
But of these 800 ancestors of yours, 650 have spent their life in caves.
Only the last 70 had any effective means of communication with each other.
Only the last 6 saw a printed word or could measure heat and cold with any precision.
Only the last 2 used and electric motor.
Most of the items that make up the material world today were developed within the lifespan of the 800th Person. (That's your dad )
Inspired from: NASA report SP-5067, 1966