The M-Ratio is measured by the total cost of each orbit including the blinds and antes. For example, if we have 10,000 chips, the blinds are 100/200 and the ante is 10, and we're at a 10-handed table, our M-Ratio would be 25. This is calculated as 10,000/(100+200+(10*10)).
"That's poker" is a colloquial expression often used to convey acceptance of a situation that is out of one's control. It's derived from the game of poker, where luck and chance play a significant role in the outcome. Essentially, it means "that's just how things are" or "that's life."