I always love organizing my Illustrator design with layers and symbols, with the right hierarchy of layering, I can easily move or transform any groups of art. One thing keeps baffling me is that every time I copy and paste layers of art, Illustrator would flatten all the layers. This is like removing all the folders and shelves which help neatly partition the papers.
It was not until today I came to realized that Illustrator does provide an option to retain the layers, the option is named “Paste Remembers Layers”. It can be activated through clicking on the option menu of the Layer panel.
I wonder if Adobe has any reason not turning this option on by default, but in case anyone from Adobe cares, please … this saves time and lives.
Update: There is one major drawback of the “Paste Remembers Layers” option – any paste executed would be pasted as top-level layer. In other words, if one wishes to paste a set of layers inside another layer, one would have to paste and then move the newly-pasted top-level layers into the desired layer. Rats.