We typically don't give much thought to inflation, but over long periods, it can wreak havoc with the purchasing power of our dollars. Over many years, inflation has averaged about 3 percent annually, though there have been times when it has been very high and very low. In 2015, for example, it averaged close to 0 percent, while it was 6 percent in 1982, 9 percent in 1975, and more than 13 percent in 1980. Even at 3 percent, it can really shrink the purchasing power of your future dollars, as something that costs $100 now may cost about $243 in 30 years.