Yep, depends on your memory context capacity.

For me I often don't feel any pain-points when working before about 1kloc (when doing JS), however if a project is above 500loc it's often a tad painful to resume it months later when I've started to forget why I used certain data-structures that aren't directly visible (adding types at that point is usually the best choice since it gives a refresher of the code at the same time as doing a soundness check).