Spongebob was 8 when Patrick was 12. Spongebob is now 40, how old is Patrick?

44
S=8
P=12
P=S+4 at all times
S=40
Therefore P=44

Patrick is 12. Patrick is a cartoon. Cartoon characters rarely age.

Consider Maggie Simpson, she was “about 2 years old” in April 19, 1987 when the world first saw her on the Tracey Ullman show. Some 30 years later she is still “about 2 years old”

As for SpongeBob his driver’s license says his birth date is July 14, 1986,

In September 24, 2004 his creator Hillenburg joked that he is fifty in “sponge years”. So he would be 73 now if he aged.

Patricks birthdate is 19th July 1984.
Even if they did age like humans, Patrick was never 12 when Spongebob was 8.

Patrick is 71 in “Starfish years”. Hope that helps.