At what point do you begin to worry about milestone regression? My DD used to roll both directions without trouble. Now when I put her on the floor she just lies there. I wouldn't be overly concerned because I know this sometimes happens, but my daughter was born with congenital CMV. Although we've been very lucky so far to not have any problems, learning disabilities is a possible sequal from the condition. If I'm remembering correcrly, I was thinking that forgetting a milestone skill is a possible sign of LD.