“I did the best that I can do”, is a very common cliche, especially used by a lot of parents
on their adult or teenage offspring when complaining about previous treatment.
I see this as a well worn pathway (in our brain) and as smart as we are getting today, modern parents still fall for this notion, having not been able to counter such a claim by their parents.
Here is a few tips if you are a parent and seem to think that this statement applies to you.
If you also think that the statement “I can do better” applies to you then I don’t think that it is possible that you can be “doing the best that you can do” at any given moment, like now. You might then argue “but I am donig the best that I can do with what I know at this moment”. I would counter that by saying that you could have known more, now, if you had read a text book yesterday rather than watching the Simpsons, for example.
Nothing wrong with watching the Simpsons but I thnk that their existence takes away our right to claim that “I did the best that I can do, with what I knew”, when we could have always known more.
So why do we do this to our children, dress ourselves up to be…..well , perfect at any given moment? Why not simply put up our hand and say, “you know… you are right, I could have done better, I am not perfect and thanks for pointing that out and giving me something to think about and work on.”
I guess one of the reasons is that if we, as parents do not have this awareness then
there is not much chance or our offspring having this awareness either, especially in their teens. So when they come to their parents to complain, they are not likely to complain in the “best way that they can” and we end up with a cycle of blame and counter blame on both sides, for not doing their best when making a complaint.
If we all had a better understanding of this principle, that we all “could have done and can do better”, then parents and children would not be so surprised when our next delivered complaint was not so well delivered, and their would be a lot less shooting of the messenger and a lot more appreciation of the opening up of a new and difficult and not so perfect discussion.
rethink PERFECT 
Funny you say that about parents in relation to their kids i.e. “I’m doing the best I can”. Because I’ve heard adult children say the same thing about their parents i.e. “she’s doing her best’.
I guess its understandable in a way, because if I can excuse someone’s behavior “as their best” then I don’t need to confront that behavior with feedback on how I would prefer to relate. With the thinking being “if they are doing their best then the status quo is the best I can hope for”.
If my child said that to me I think I’d find it a little Condescending (not the Greek parachutist), given I’d appreciate the feedback because I want to constantly do better. Rather than to be pre-judged as someone who can’t improve.