Anyone who's lost someone to cancer will say this, that you have to struggle to try to remember the person before the diagnosis happened, because they really do change - as anyone would change.
"Ahu" are stone platforms on which many moai sit. There are 313 known ahu and 125 of these carry moai. The biggest, Ahu Tongariki is 220 m (720 ft), and had the most (15) and tallest moai.
There are potentially more than 170 billion galaxies in the observable universe. Some, called dwarf galaxies, are very small with about 10 million stars, while others are huge containing an estimated 100 trillion stars.