Sorry to be a snob. If you ain't made a Will yet, then you're irresponsible.
Or possibly you already have made one but your circumstances have changed, such as divorce (not in my case), acquisition of step children, acquisition of complicated assets, desire to leave a legacy to various others (including charities) who weren't mentioned on earlier will(s) etc. Lots of reasons why someone who already has a will might want to make a new one.