twenty centuries in perspective

I was just reading an article in which the author was talking about looking at something from the 19th century from a 20th century perspective, and I thought, 'it is now the 21st century.' We are actually 13 years into the 21st century. How time flies! Then it occurred to me that if you had only twenty people who lived 100 years you can go all the way back to the time of Christ! Only 20 people! It sure makes those 20 centuries seem like it wasn't all that long ago.