Most people put others first.
This may sound like a noble deed but, it can cause all kinds of problems:
If you put others first all the time, you'll neglect yourself. You lose touch with what you want, neglect what you need and thus don't get what you want. If you do this long enough, you'll become frustrated and resentful while others will take your sacrifices for granted.
Additionally, if you constantly put others first, you create problems for yourself.
When your life revolves around doing things for others, you can't solve your problems. You'll simply lack the time, energy and resources to do so. Thus, the problems will stay around, grow and plague you and the people in your life for years. That's a terrible situation to create for yourself.
Lastly, you might lose yourself in pleasing others.
If you orient your life around the needs, wishes and expectations of others, you'll lose touch with yourself. You won't know your deeper wishes, hopes and desires. Not being in touch with yourself, leaves you disoriented, aimless and unhappy. Worse, it might increase your motivation to please others to avoid your problems.
I know this because I used to put others first all the time.
I prioritized what my family expected of me more than my own needs. When they wanted to talk, I'd pick up the phone. When they expected me to visit them, I visited them. When they advised against a decision I went along with it. I prioritized the approval and happiness of my family at my expense.
As a result, I suffered from most of the problems outlined above:
I didn't fix my problems because I was trying to appease my family. As a result, those problems grew over time all by themselves and slowly made me miserable. I didn't set and maintained clear boundaries because the concept of boundaries was foreign to me. As a result, I lacked the courage to stand my ground, make my own decisions and forge my own path.
In essence, I used to live more for others than for myself and this made me unsuccessful, resentful and unhappy.
The Benefits of Selfishness
I didn't know it at the time but being selfish isn't necessarily bad. If someone wants you to think that, they might guilt trap you so you conform to their expectations.
In fact, selfishness is essential for a happy, healthy and good life.
Selfishness is necessary to establish clear and healthy boundaries. Boundaries help you to say no when you need to and defend yourself against unreasonable demands. They allow you to stay consistent enough to fix your problems and improve yourself. Then, you can not only live a better life yourself but be more capable to help others.
If you don't assert your own needs and desires, no one will.
Good and Bad Selfishness
That being said, I don't tell you to be selfish all the time. That would just make you an asshole. The key to being selfish in a good way is to be selfish for good reasons. Allow me to explain:
There are two types of selfishness: lower and higher selfishness.
Lower selfishness is what most people think of when they hear the word "selfish." It focuses on satisfying your wants at the expense of others. You might even take advantage of others because it's all about satisfying your narcissistic tendencies. Needless to say, this is bad and you shouldn't do it.
Higher selfishness is based on an accurate understanding of yourself. It's focused on the higher motive of serving others well over the long term. It's grounded in the realization that you can only serve others well if you take good care of yourself first. You need to be strong, well-supported and happy to support others well over the long term. Otherwise, the additional demands on yourself will slowly grind you down.
The key is to focus on your good selfishness and avoid your bad selfishness.
Discerning the two isn't easy. It requires a deep understanding of yourself and absolute honesty with yourself. You need to know and understand your motivations, desires and dreams. When you do, you can become aware of when you want to follow bad selfishness and stop doing so.
This self-awareness will also help you to notice good selfishness. Then, you can lean into it to put yourself first in a healthy and beneficial way. This can be hard at first but becomes easier with practice and time.
In sum, always putting others first is only superficially a good idea. In reality, it can cause tremendous problems that can make your life worse. Leaning into selfishness is a good way to counteract this tendency. But, it's crucial to discern good from bad selfishness and lean into the former while avoiding the latter. Then, you can be selfish in a good way.