NO baby or child is sweet and perfect all the time.
Childhood... goes on for YEARS.
And for that whole while, they will go through MANY developmental/emotional/cognitive phases.
It is normal.
But, if expectations upon a child, is not age congruent... then there will be problems and frustrations, for the child, then the parent.
Expectations and actions upon a child, needs to be age appropriate.
Emotions in a child, isn't even fully developed yet, even in a 3 year old. They don't even know the names for ALL their abstract feelings yet nor do they have the communication skills for it etc.
In a baby, ALSO know that... because they don't have communication developed yet... they may, tantrum/scream/yell... because they are trying to SHUT-out... external stimuli which is... irking them. Babies/kids get irked too. But they don't have the skills to cope. Coping skills are not an automatic skill. It is taught.
Know your child's cues.
Then from there, you can distinguish... IF your child is irked/unhappy/grumpy/tired/hungry for whatever reason... or if it is because they are frustrated. Which is common. Because, they are not fully developed yet nor do they even have fully developed deductive and inductive reasoning skills yet nor the ability to analyze... every given situation.
And, kids also go through sound and voice phases. They scream or yell trying out their new found sounds.
They "hit" as they are developing more motor skills... and the cause/effect understanding of things.
Kids... that age don't even know, how to manage when "mad." Not even some adults know how.
Sure, as he grows up, a parent teaches concepts and boundaries and what not. But, they don't learn this ALL at one time. Certainly not now at 17 months old either.
A kid that age doesn't even know... what "aggressive" is.
They don't even know social concepts nor are they even fully socialized yet. At this age as well... they do not play interactively... they do what is called "Parallel Play."
And in the basic scheme of things: a baby/young child... gets very fussy and tired, when they don't nap and when they are hungry.
So again, it all goes back to, knowing your child's cues.