There is no if, there have been those who have lived in caves...
Heb 11:37 They were stoned, they were sawn asunder, were tempted, were slain with the sword: they wandered about in sheepskins and goatskins; being destitute, afflicted, tormented;
Heb 11:38 (Of whom the world was not worthy
they wandered in deserts, and in mountains, and in dens and caves of the earth.