The prayer of St. Francis of Assisi reminds me of another famous prayer, the serenity prayer.

"God grant me the serenity
to accept the things I cannot change;
the courage to change the things I can;
and the wisdom to know the difference. "

According to Wikipedia, these lines of prayer were written Reinhold Niebuhr for a sermon.

Wikipedia also quotes some humorous versions of the prayer now in circulation:

1. God grant me the senility to forget the people I never liked anyway,
the good fortune to run into the ones I do,
and the eyesight to tell the difference.
– Author unknown
2. God grant me the serenity to accept the people I cannot change
courage to change the one I can change,
and wisdom to know it’s me.
– Author unknown

To me, the first one can be called a humorous one, especially with the play of word pairs such as serenity(being calm and peaceful)-senility(being confused and absent-minded), courage(intrinsic)-fortune(extrinsic) and wisdom(mental)-eyesight(physical). For the second one, I think, if being rewritten, it will be a human version to the original "things" version.

May I have the serenity to accept the people that I cannot change,
the courage to change the one that I can change,
and the wisdom to know that I am THE ONE and the only one that I can change, and the difference between how to treat the others and how to treat oneself?

This simple prayer, either the things or the human version, is easy to say but difficult to follow. Perhaps this is the purpose for saying a prayer. Though, I believe, a prayer is in itself a promise, not from the others, but from the one who says it.

For the human version, it is easy to obtain the wisdom (the intellectual domain), but it is rather difficult to do the rest.
It is quite natural to know that we cannot change other people, but it is quite a challenge to accept that with serenity (the affective domain). We are used to be angry with those who fail us or those who do not like. And it is often hard to distinguish the person and the deeds, and it confuses us which we cannot accept. Perhaps the deed makes us angry and the person makes us sad, but still we fail to accept the person plus the deed with serenity.
And it is usually natural for us to tell what and how other people need to change, but it is totally a different story if the subject is I.
Sometimes we may not notice the need for the change (intellectual domain). Sometimes we may not want the change (affective domain). But most of the time we simply do not perform the change or make it our deliberate but common practice (action domain). We may be lack of courage, the courage to be different.

For the things version, the challenges are different. (luckily, I am serene enough to tell the differences.)
We do not lack courage to change things. Perhaps we have reached the evolutionary stage of expecting anything changed or updated from time to time. (examples? the design of this blog, the telephone models, the menu of McDonald’s and the monthly charge of internet services. Enough?)
(if you want to argue that people may be very stubborn, then please refer to the preceding section.)
In short, we are action people. And as survivors of this fast changing and ever improving society, we do learn to accept that things may not change according to our wishes, needless to mention that our wishes may be internally conflicting. Perhaps we need serenity to accept things changed and changing more.

Look, this is the real challenge for us. See, I have forgotten that there are things better unchanged. (what? I am not working for the HKSAR government. I am not talking about the political issues. I am not working for the developed countries. I am not talking about the environmental issues.)
We have courage to bring out changes and we even have serenity to accept changes, but we forget, or do not know that there are things that cannot be changed or better unchanged. We need the wisdom to tell the differences. And we need the courage to keep the things better unchanged unchanged.

Reflecting on the describing the human version as humourous by wikipedia, I now find that it may be correct. The human version is not a paraphrase of the things version of this serenity prayer. Taking the human version of facilitating changes as the things version of facing changes may be humourous, but some time it can be hazardous. (see, i am more than serene, ha ha!)

Perhaps let us keep the serenity prayer unchanged:

May I have the serenity to accept the things I cannot change;
the courage to change the things I can;
and the wisdom to know the difference?
(I cheated. I have made a change again!)