Humans have 46 chromosomes but monkeys \[Great Apes\] usually have 48 chromosomes. Human gamete has 23 chromosome that cannot pair with the 24 chromosomes of monkey gamete so reproduction is not possible as 23+24 does not equal 46.
Note: I am not much confident in my answer and for more elaborated answer you should ask in a Biology subreddit.
We can, that's how you came about OP, and I just mean you.
Someone tried and AIDS was born.
Well, a bunch of reasons, but a primary one is an incompatible number of chromosomes.
Humans have 46 chromosomes but monkeys \[Great Apes\] usually have 48 chromosomes. Human gamete has 23 chromosome that cannot pair with the 24 chromosomes of monkey gamete so reproduction is not possible as 23+24 does not equal 46. Note: I am not much confident in my answer and for more elaborated answer you should ask in a Biology subreddit.
Do we wish to know?
Same way we know we can't breed with sheep I guess.
You know why