What is a grom and why are people calling me that everytime I surf

It means your a young surfer and that your good at it. Dont feel bad its a complement.

Dude it means you are rad

if you do not know what it is you are one
it is not meant to be mean
with experince you will shed the title
do not worry about what others think
have your own style
and stay on the waves

Asked and answered at least 3 times here.

http://au.com/question/index.php?qid=20070519113831AAbKlyy

a grom is the youngsters just starting out in surfing normally sticks until in the teens

it means that you're a ripper under 18 years of age. i'm a grom too.

a surfer before they hit puberty

yep, that is you but also what you are not realizing is it is good to be a grom because that means you got a head start on surfing. you're a kid surfer is what they are saying.
i'm 16 and still learning. l started at 15 which was the year after l moved to costa rica.

; ) you're cool