Im not actually sure if anakin ever met grevious in the clone wars

I don't think he ever did because plot convenience

Plot convenience?

it was a running gag spawned with these 2 lines

Ok

Grevious and anikin never actually met during the CW

The deeper meaning in Anakin's line: General Grevious. You don't have the high ground.

Anakin never actually met General Grievous during the Clone Wars - at least, not in person.

I think Ahsoka must've told Anakin about her first duel with Grievous - which was back when she was still a young padawan - so she most likely overexaggerated his height. Her description of Grievous must've been what Anakin was truly expecting, as he had never actually met Grievous himself. It'd be really funny if this was the case.

Woah. That actually makes a lot of sense