No one really likes to be wrong or to take blame; it doesn’t feel great. However, you also learn from mistakes and consequences. They are a big part of life and growing up. Taking responsibility is a big lesson. It’s still a bit hard for my girls to learn and accept at 5 and 2.5.
My girls get upset or cry if we tell them something they are doing is wrong. This is mostly due to the fact that they could hurt themselves or I’m in a rush and want to help them. The 2.5 year olds don’t have much of a concept of responsibility, but I’m working on it with my 5 year old. I have no doubt that instilling this value at a young age will help in the future.
I’m starting to talk about it very openly with my older daughter, using her toys as an example. We’ve had several nights where she cannot find her beloved blanket or most recently “Elsa.” I do not encourage her to take her blankets from her room for this reason. At bedtime she gets upset and worked up about finding them. If she leaves them in bed in the first place there is no hunting through the house right before bed. This is a first small step to introducing an idea that she is responsible for having those items on her bed waiting for her.
Most recently she cannot find one of her gorgeous, giant, clip-on heart earrings. I clearly explained to her that she is now responsible for keeping track of her toys and she needs to find a place to keep them. To be honest, I have too many other things to juggle than finding a plastic earring. She is old enough now to keep tabs on her things.
My husband has also given our 5 year old a “job” as well. Her “job” is to help put the twins’ cups in the sink in the morning. We are trying to incorporate the idea of responsibility and accountability in small ways. There are many different age appropriate activities to incorporate in everyday. 
I plan to continue to keep on encouraging her to be responsible for her things and then she will hopefully transfer that to her organization skills and be a good role model for her sisters as well.
