Players draw resources, commodities (Cities and Knights), and fish tokens (Fishermen of Catan) during the course of various Catan games. It is almost always advantageous to draw your earned "goods" whenever possible, but is it required?
Forgetfulness
Players sometimes forget to draw the goods they are entitled to. If play passes to the next player before they remember, we often forbid the forgetful player from drawing what they forget. They should learn to pay attention, although I am very lenient with new players.
Strategy
I was recently in a situation where purposely not drawing all my goods would have been to my advantage had a certain number been rolled. A player may do this to avoid having more than 7 resources in hand when a win is otherwise clenched, or to avoid drawing the Old Boot in Fisherman of Catan (which requires the owner to have one additional victory point to win). Had someone reminded me to draw all my goods, I might have suspiciously declined.
What do the rules say (or imply) about this? Are players required to draw all their goods? Are forgetful players allowed to gather previously forgotten goods?