1) I am aware of inflation, but my calculations shown don't consider them. A dollar today has slightly more then half the value it will have in 2055 if you assume yearly 2% inflation. I suspect we will have a few years with much more than 2% inflation between now and 2055 and we might be finished with years with very low inflation for awhile.

2) 8% returns at 2055 is a bit optimistic, but not unrealistic. I won't mind if I have to adjust the date +- 10 years to time the market. I feel comfortable putting the majority of my assets in the US stock market, but I do have some assets independent of it. The last the stock market crashed substance farming was popular.