Back to good health with my Macintosh

There's no better way of making sure you're in good mental and physical health (of a psychological kind) than to decide to carry out an update to the latest version of the Macintosh operating system. So, as of the end of the afternoon, I've acquired (for free) the latest El Capitan system.

Did I really need this latest version of the Macintosh operating system ? Of course yes, it proves that I've still got basically the same cerebral system (mine, not that of my computer) as before I had my accident.