Renew, Refresh (but not Reuse)
I don't know the exact statistics regarding how many of us ever execute a Will, but it's alarmingly low. Perhaps a secondary effect is my observation that, of those who do make the effort (and it is an effort) to execute estate plan documents, few ever review, update, and re-execute.
An estate plan is a living and breathing creation, affected over time by changes in one's personal and financial lives, and by changes in the economy and in tax and non-tax law - matters that are constantly in flux.
Regular review and refreshing of one's plan and plan documents are crucial to success; I generally advise my clients to set a tentative meeting for two years after documents are signed.