In his graduation speech, darian did well at the beginning and the end of the speech but faltered in remembering the information he wanted to express during the middle section of his speech, which illustrates the effect.

This illustrates the "serial position" effect.

Serial position effect is the tendency found in people when in a situation when they need to memorize an information etc. they tend to have better memory of the earlier or starting points and endings while having worst memory of the middle section. Ebbinghaus discovered the serial position effect.