The size of your dreams must always exceed your current capacity to achieve them. If your dreams do not scare you, they are not big enough.

These words are another way of saying that we need to dream big. They go further by specifying exactly how big our dreams should be. Our dreams should be so big that given our current capacity alone, we won’t be able to achieve them. They should be so big that they scare us.

Her Excellency Madam Ellen Johnson Sirleaf, former president of Liberia, said these words during Harvard University’s 360th commencement, in 2011. She was the commencement speaker. Harvard University is her alma mater.