What is 75 hard?

One of the best mental toughness programs out there that I am aware of is 75 hard. Check out my progress picture in the video, it was a great physical improvement, but you won't be able to see the mental growth, which is where I benefited the most. I highly recommend this if you are looking to make huge improvements in life. This is a momentum builder like nothing else I know of. Would you ever do this?