Memory foam sounds ideal in theory—it contours, conforms, and softens as body heat hits it. But as you sink in, you eventually hit the limit of compression, transforming that soft feel into hard pressure against the foam underneath.
More importantly, highly conforming foam can reinforce bad alignment. If your neck is rotated or flexed, memory foam accommodates that poor position rather than supporting you out of it. Think of a worn-out pair of soft shoes: they feel comfortable initially, but over time, they break down around your poor gait and lock in bad mechanics.
Add in polyurethane VOC off-gassing and heat retention, and memory foam becomes a tough sell for hot or sensitive sleepers.
Read Post 5 to see why natural latex offers a far superior, responsive alternative.