This video is quite short and can be, for some, difficult to understand. So, here is a transcription of a direct quote from this important and newsworthy video, so you can study this boy's message more clearly:
Bollocks! BOLLAX! BALLAXE! BOLLECKS!
For those of you who do not know, according to dictionary.com, this is the definition of "bollocks":
Bollocks: (n) 1. another word for testicles 2. nonsense; rubbish
Now we can only assume this newly made humanoid learned this swear word from his extensive reading habit and his thirst for knowledge.
We can then extrapolate why he is laughing -- for he is filled with joy at understanding the particular etymology of this centuries-old swear word and how, with words like these, we can commune with our ancestors.
This is the only explanation for both the boy's fascination with the word and him finding it so humorous. No other exists, as far as I can see.
I just hope the young ones of our nation follow this little boy's lead and develop such a passionate interest in etymology. I'd like to suggest the word “fuck” or “dingleberry” for possible study.