I am not a native english speaker and I am not sure if a I made a mistake using this sentence. My intention when I used this sentence was to make a compliment for a person who is much better than me in something (and older than me too) and I will want to reach the skill of this person someday. So, I commented:
When I grow up, I want to be like you.
And the person replied:
Ha! Looks like you may have a few more years before you catch up to me, little whipper-snapper!
As a non native english speaker, I was confused because of the last expression whipper-snapper.
Now, I don't know if I was offensive and get a rude reply. Or I was polite and get a rude reply. Or the conversation was normal...