For David, Adullam was a place of refuge, after he'd, by the wisdom of God, escaped being killed by Goliath's village people. For the distressed, indebted, and discontented folks, who later became the mighty men of David, Adullam was their last resort. However, the brothers of David never saw Adullam in light of the foregoing; for them, it was just a low land they went down to, in order to be with their brother. No wonder none of them emerged as one of David's mighty men. It matters what mindset you carry to Adullam.