He is not 5.
Is he in preschool or Kindergarten?
Kids, regardless of gender, learn and "memorize" things, at different pacing.
Normal.
Do not, compare your kids to each other.
They are 2 different individuals.
Also, no kid, from Kindergarten to 12th grade, will get, "straight A's" each and every single time in each and every single subject or grade level.
And if a kid does not get straight A's.... each and every time, it does not mean, they are lesser of a student. Or not as "smart."
Your son, is only 4.
My son, had only 6 months of Preschool. Then he went to Kindergarten at 4 years old, then turned 5. He could enter Kinder per the age cut-offs for the school. At that point, he did not know EVERYTHING. In Kindergarten they still learn the ABC's and counting etc. It was, no problem. He had no "learning problem."
Kids, all learn, at different... pacing.
Kids, do not learn, all at the same, pacing.
Even my son's Kindergarten Teacher, said NO worries!
My son is in 2nd grade now. And he is real bright.
But, all kids, have an aptitude for certain things, versus other subjects. Normal. JUST like, adults.
The MAIN thing, that a kid needs to learn... is that: it takes WORK and liking to learn... in order to be, "successful" and do well, in school.
Just because another kid seems "smarter" than another kid, it does NOT mean, that kid is... better or "smarter" than the other kid.
Being "smart".... takes work... and it takes learning to have a work ethic. To work for it, and learn the PROCESS of learning. It is not instant.
And, some kids can easily memorize... things. But that does not mean, they comprehend it. Nor that they can them summarize or write an essay on it. Memorization is different, that comprehension.
MANY successful people, child or adult, are successful because, they worked at it, and went beyond.... what they had to do, in order to research and learn... a subject. And NEEDED help.... with learning, what was needed to be learned.
Needing help with learning or not needing help with learning... does not equate to whether or not a child is adept, or inept. At academics.
I have a son and daughter.
I don't compare them to each other.
They are both different.
And it is not just about gender.
If it were, then all boys... would be "slower" to learn the alphabet, than girls.
And that is just not so.
I also work at a school.
And, differences in kids, cannot all be just "blamed" on gender differences.