The earth is 4 1/2 billion years old. Life on earth, at least 3 1/2 billion years. It is tough to actually imagine a billion years.
Generally accepted dates for the beginning of human history are ~2-300,000 YA. Hundreds of thousands of years is still a lot of years, but we can visualize thousands and hundreds. 100 pennies is a small pile, one thousand pennies is 10 times those small piles, one hundred thousand pennies is one hundred piles of one thousand pennies :) The leap to millions and billions is kind of abstract though. One billion is so many pennies.
A billion years ago a shallow sea covered the area of Utah I am at. You don't have to be a geologist to see that some serious geological shenanigans happened in the intervening years. From Provo south to Springville you can see that many different layers of rocks were folded in waves and taco'd before being uplifted into mountains. The waves of stone are incredible to look at.
I have posted about Rock Canyon in Provo before
Layers of pre-Cambrian shale and siltstone deposited by the shallow sea (~1 billion - 800 million years old) are exposed part way up the canyons, above much more recent sedimentary material deposited by a giant lake that used to fill Utah Valley until ~14,000 years ago (Lake Bonneville).
This weekend up Right Fork Hobble Creek Canyon we found fossils from the pre-Cambrian sea, specifically oncolites. Oncolites are sedimentary structures composed of oncoloids, ovoid structures created by cyanobacterial mats growing around a seed object such as a piece of shell or rock. The encrusting microbes deposit a calcium carbonate layer, which expands outward in rings during successive growth.
You can see the growth rings well here:
I repeat - these rocks contain evidence of fossil life from 800 million to one billion years ago. Seriously mind blowing.
We also found a lot of garter snakes in and around the creek.
BYU Geology Studies Vol. 9 Pt. 1 - Geology of the Southern Wasatch Mountains and Vicinity, Utah