Well into the 1980s, doctors would perform open-heart surgery on infants without giving them pain-relieving drugs. This is hard to believe: By the standards of contemporary medicine, not to mention common sense, the practice is akin to torture. Yet then-conventional wisdom held that babies did not feel pain, at least not in any meaningful way. Their brains and nervous systems were considered undeveloped. And regardless of what they felt, they wouldn't remember it.