who was the black lad who simplified memes

It sounds like you mean the meme known as “Disappointed Black Guy”. The person in that meme was identified in a Know Your Meme interview as a man whose identity was revealed years after the image first spread online.

What it was

• The meme is a reaction image of a Black man giving a deadpan, disappointed look.
• It became popular as a shorthand for disbelief, judgment, or “really?” energy.

Why people talk about it

• People often remember the image more than the person behind it, so his identity stayed a mystery for a long time.
• That’s why the question comes up so often when people ask who the “black lad” in the meme was.

Quick note

• If you meant a different viral image, the most likely match is the one above, but the wording you used is a bit vague.