a The reason the previous boss/coworker want me back is ...

The reason the previous boss/coworker want me back is that I did a great job and I'm very nice/reasonable guy.

When I left the company, I told them the real reason and why I think the project in the new company is promising (of course, did not happen). The boss said: I'm happy for you and at the same time, I'm sad for the company since you would leave. I gave 2 week notice, and also still provide some help once a while when I was free. Further more, the CTO told me: they interviewed more than 20 candidates since I left, but did not hire anyone yet since they try to hire a person similar to my level.

I think this is enough to explain why previous coworkers are happy to see me back (although I did not 100% decided to go back yet, but I definitely will leave current company soon).

This is also the reason I know my ability and the current boss is bullsh*ting, :)

why you think "我認為你老板看錯人了"? if you do not mind, please explain. Thanks.