Childhood. The image being that the age was young enough to still sit on the mother's lap.
New words, one handy idiom, and a 2-minute quiz — delivered to your inbox to keep your streak alive.
DirtyGame"I was radicalised on my mother's knee"It implies that your mother was a radical, and taught radical ideas to you when you were very young.
AlpheccaStarstaught radical ideas to you when you were very youngSee also, "red diaper baby".