What does it mean if the standard deviation is equal to the mean?

A large standard deviation indicates that the distribution is heavily weighted far from the mean. Take the following example:

{1,1,1,1,1,19,19,19,19,19} Mean is 10 and StDev = 9.49

Now look at this data set: {5, 6, 7, 8, 9, 11, 12, 13, 14, 15}

Mean is still 10, but StDev = 3.5