I don’t use that often, but if I do, it’s usually in a situation where I have too many things going on all at once and something has to give. I only have two hands.
My personal favorite, favored by politicians: “Mistakes were made.” Not that he made mistakes himself, you understand. The mistakes just kind of happened all on their own. 
I think self-acceptance starts with realizing 1> I am not perfect, 2> neither is anyone else, 3> as long as I am sincerely doing my best, that’s okay.
I have bad days. Sometimes I get so upset that I snap at someone. Generally I realize how over-the-top my reaction was right away and I immediately follow it up with a “Crap. You didn’t deserve something that harsh; I’m sorry.”
Do you need to stay home when PMSing? No, I don’t think so; but I think what you can do is make an effort to be consciously aware of how you’re feeling when you are, and realize where it’s coming from – which, for me anyhow, helps me to divert the irritation before it blows up. If I know when walking into the office that I’m in a state where little dumb things are likely to set me off, I can focus more attention to reminding myself that while it’s setting me off, it really is a little dumb thing, and hopefully that kind of self-talk will diffuse the blow-up before it happens. This isn’t a perfect system either, so I also employ the follow-up apology as needed; and if the people around you are decent human beings, they will do their part by not judging you overly harshly because you’re having a bad day. Sooner or later they’ll have a bad day, too.
Relationships are inter-relationships; that kind of give and take is necessary for them to work, because we all are only human.
I think it’s good to recognize that you’re not perfect, but when you do that, own up to your imperfections genuinely. Saying, “I’m only human” or “Oh, you know me” is so general it really doesn’t convey any sort of understanding of what your imperfections are.
For example, my mom said, “I’m only human” after spending my son’s birthday bitching about the number of people around, the noise created by said number of people and vocally wondering when said people would go home. After I got irritated with her for it, she said, “Well, I’m only human,” which told me that she wasn’t sincere at all and really didn’t understand or care to understand why I was upset. Had she instead said, “You know, I didn’t mean to make others uncomfortable just because I was upset. I’m not used to so much going on,” I would’ve let it go. But since this repeatedly happens and she obviously has no clear understanding of why this is bad and why I’m getting upset, “I’m only human” has become a hollow excuse for bad behavior.
So bottom line, I would say it depends.
I’ve used it sometimes. What can I say – I’m only human.
Well, yes and no. “I’m only human” is sometimes a good reminder when we are pushing ourselves too hard. I didn’t run 5 miles today only 2. If it is used as an excuse for bad behavior then it is avoiding reality.
I like the acceptance prayer and you can substitute anything in the alcoholism and sober line. Also you can put “the” in “Gods” world if it fits better. This really shows me what is bothering me, that I need to accept it, and I am the problem and in me is the solution.
Acceptance Prayer
Acceptance is the answer to all my problems today. When I am disturbed, it is because I find some person, place, thing or situation ~ some fact of my life ~ unacceptable to me and I can find no serenity until I accept that person, place, thing or situation as being exactly the way it is supposed to be at this moment. Nothing, absolutely nothing happens in (God’s) world by mistake.
Until I could accept my (alcoholism), I could not stay (sober), unless I accept life completely on life’s terms. I cannot be happy. I need to concentrate not so much on what needs to be changed in the world as what needs to be changed in me and my attitudes
From The Big Book of AA, pg.449
I’m only human
Of flesh and blood I’m made
Human
Born to make mistakes
