Breathing and swallowing are regulated by the medulla, the most primitive part of the brain. A fetus can involuntarily yawn, swallow, and suck by the tenth week of gestation.
The cerebral cortex however, takes much longer to develop, beginning late in the second trimester and continuing until a person is around 25 years old.
This can be readily observed in the dishonest and malformed opinions of the ignorant child responding in this meme.