I think that even though we may set out to do things which may ultimately fail does not affect Yoda's teaching here.
He is saying, I think, that if you are going to do something you must start with the intention that you are going to do it and finish it. If this is your intention you have a much greater chance of success than if your intention is to just, try.
"Doing it" implies that from the offset you are going to succeed.
"Trying it" implies that you expect a possible failure.
So, there is no point in doing something if you think you will probably fail. So only do it if you are indeed going to...DO IT!
Re: Do or Do not...there is no trying (Do you agree?)
I guess it depends how much effort you put into it. But saying that, it is about accomplishing something like a career or something you want to achieve. If you are talking about a relationship, then it does take two, two, two minds that are N'SYNC.
__________________ Deja Moo: The feeling that you've heard this bull before.