I mean why do I have to say {loSmaH wej ben jIboghpu'}?

Maybe I wasn't born. Maybe I was grown in a test tube, maybe someone found me growing on a tree, maybe I suddenly materialized out of thin air.

Maybe you can say loSmaH wej ben loD. We know you can say cha'maH ben HIq.

Is this {x ben boghpu'} some kind of klingon crap in the spirit of "klingons are inaccurate but never approximate"?

No. We have that form from someone asking how to say How old are you?, not someone wanting to state their age.

-- 
SuStel
http://trimboli.name