Is "Be yourself" a good advice and how should it be understood?

Most of us are told to be ourselves, usually seen as not trying to pretend to be anything else. However, on other hand we are told to act differently to take others in consideration.

If I'm not doing enough homework, I might get told to participate more and take my share of chores instead of letting my wife do everything. Even though I would perfectly be able to be myself lying on the sofa while my wife is cleaning the apartment. Why isn't "being yourself" good any longer?

The difference is though, that I can be myself even though I think of others. I can be myself even though I change as a human, as the idea of "me" is not set as one simple thing, otherwise we wouldn't be ourselves after we have been babies, as we all grow and change as people through our lives.

One might however see that the core of "ourselves" would be something in our core personality, as we are told that there are some basic characteristics in us since we have been babies and they would never change. I'm not going to say if this is true or not, but as long as we don't take it as far as one of my friends took and told me that she's never going to change, as otherwise she wouldn't be herself. According to her, she has stayed completely the same since she was a small child.

I doubt her words a bit, at least she has changed in my eyes.

But the difference in being ourselves and changing is that even through changes, we are ourselves. However if we pretend to be something without changing, then we are not ourselves. I can pretend to like dogs when I'm at a date, but if I do not like them, it's fake. Not real. Not myself. I could be honest and not pretend to like dogs and I could still start to like dogs. During the date, I could see the dog of the date and then notice it's an awesome dogs (as dogs are awesome) and then notice I like it.

A friend might see that and say "You're not being yourself", but it's not up to others to decide what you are and aren't.

It's not only the others who can have a strong opinion on what you are as yourself. Some people might have a extremely strong feeling that this is a part of me and might hold onto it almost being crazy.

I am a man. I like cars. I love soccer more than ice hockey. I love only women. I love rock music over any other music.

What a shock would it be to notice the guy would prefer blues music over rock music? If we notice we might not be what we assume or want ourselves to be, we can meet an internal conflict. Is this me, who am I, what am I?

Sometimes I see the words "Be yourself" as something which might make it worse. Can it make someone holding onto what they have been before, refusing the change? As we all change and we will not be completely the same forever.

At best though, it is seen as holding onto what you truly are instead of trying to pretend to be something else. We just have to keep in mind, we can change as people and we aren't pretending.