Let's work this out with numbers just in case
Were just going to use the "12" from 2012 for now, we will move on to the more advanced stuff later. If we are going to add 8 to 12, then we should count up one from 12 each time, so 13 (1), 14 (2), 15 (3), 16 (4), 17 (5), 18 (6), 19 (7), 20 (8). See! We added 1 to 12 8 times, which is 12 + 8, and we got 20!
So, that means the year 2020 is 8 years from 2012!