I have been forgotten is 나는 잊혀져 왔다 or 나는 잊혀졌다. and It is forgotten just as easily is 그것은 쉽게 잊혀진다. I'm afraid to say but the answer up there is incorrect. 나 잊고 있었어 is I have forgotten something.

You are really good at Korean, aren't you? haha Amy's answer is awesome but i wanna edit one small thing. In the last sentence u asked, 눈썰미가 좋군요 is a little bit awkward in that sentence. Instead, I recommend '그는 정말 배우는게 빨라요!".

Here is one tip. As one of Koreans, I had difficulties understanding 'verb+preposition', like take over, work on, get over, break through and etc. so when u wanna use that phrase, using one-word verb instead of it, or explaining the phrase u used for your coworkers will help you to communicate. Secondly, even though u feel like that u said too much directly, your coworkers don't feel like that. Rather, it is easy to understand. so don't beat around the bush

Haha As a native Korean speaker, I hardly answer 응 back for 보고싶다. but i guess A and B are close friends and 응 kinda means 'me too' a little bit in that context. or B really adroitly tried to avoid to say 보고싶다 back to A. but i guess the former one is right.