The principle of recency states that things most recently learned are best remembered. Conversely, the further a learner is removed time-wise from a new fact or understanding, the more difficult it is to remember. For example, it is easier for a mother to recall what children were fed this morning than to remember what they were fed three days ago.
Information acquired most recently generally is remembered best; frequent review and summarising will help fixing in the audience's mind topics that have been covered. To that end, the health educator should repeat, restate or re-emphasise important points at the end of a lesson to help the audience remember them.