I can only hope my students remember what they’ve learnt in my class. If they can’t remember the vocabulary words or grammar, at least I hope they remember the fun we had.
Why do we try to end lessons on a high? Because of the recency effect: we hope that students will remember that cool and punchy activity and then somehow retain the rest of the lesson. This article from Edutopia offers an excellent collection of activities to do at the end of a lesson and create (surprise) a stronger sense of progress. My favourite by far are snowstorm and the elevator pitch (though I probably use exit tickets and ‘so what’ the most). And yours?
So, You Think You Can Teach ESL? 