Tougher than a $0.25 steak!
Stolen from some forgotten thirties movie but oh-so-applicable to my silly old dad. Medical folks were talking about a 24~48-hour period for his final breath as of Friday night. Today, he's still hanging in. He's distinctly failing, with shallow, rapid breathing, which is nastily wet, and a very shallow, thready, and hard-to-find pulse. But he ain't ready to give it up yet.
Tough? Hell, yeah. They don't build 'em like that any more.