I'm not sure that's the case. I think there's been some times (like maybe pre-Devonian), where the Earth was pretty much Waterworld.
There was a series of books that Terry Pratchett co-authored, called The Science of Discworld, where a bunch of wizards were creating a planet, and it went through a bunch of phases, punctuated by E.L.E. asteriod impacts. I think it was a fanciful chronicle of early Earth.
I avoided those books for a long time as I thought they were going to be made up explanations for how things worked in the Discworld. They're actually a wonderful set of stories and jumping off point for discussing a variety of topics. Heavily recommend them to people who may have been in the same position as me.
The geologic evidence for Snowball Earth (multiple ones, actually) is extremely strong. It is almost impossible to explain the re-emergence of banded iron formations without it.
The hard part is explain is how photosynthetic life survived. The Slushball Earth hypothesis holds that there was a band of thin ice near the equator. This has some severe problems though. For one, it isn't climatologically stable. The oceans in SE were covered by "sea glaciers," which were floating glaciers thicker near the poles, which flowed to the equator. These flowed due to the weak hydrologic cycle, with ice experience net sublimation near the equator. These would have overridden any areas of thin or nonexistent ice.
A hypothesis that is getting more traction is that narrow equatorial rift seas (like the Red Sea) would have prevented inflow of the sea glaciers enough for thin-ice refuges to exist. These kind of seas probably existed, because this was occurring as the supercontinent Rodinia was beginning to break up.
At least after formation, but also likely again after the impact thought to produce the moon, all the surface was melted, so all the water was in the atmosphere and inside the Earth. When things cooled enough for liquid water to rain down and stay liquid, that must have been some deluge.
I'm intrigued by the premise that humans are aliens who've forgotten our own origin, but unfortunately the fossil record debunks this. We're definitely from earth, at least since our very distant microbial ancestors.