Maturity

How can someone really say that they are mature.
Is there a way on how you can measure the level of maturity of a person.

Most people will say that a person matures when one can already make grown-up decisions.
Does that mean being mature is the same as being a grown-up???
And what exactly are grown-up decisions??
How can you differentiate this type of decision from other decisions??
In my opinion, grown-up decisions are those that are hard to make,
so hard that it usually hurts the decision maker.
It hurts because it usually is the one thing that you don't want to do,
but unfortunately, it is also the one thing that you have to do.

Letting go of someone you love because it's the best thing to do,
Sacrificing something very important to you for the benefit of others,
Hurting another person just to do the right thing.
All these can be considered as grown-up decisions.
All of these are also selfless acts.

So, if you make selfless acts, you make grown-up decisions,
if you make grown-up decisions, then you are mature.
therefore, being selfless means being mature???

So what's wrong about being immature??
what's wrong about thinking of yourself first??
Is it so wrong to be selfish??

I think maturity doesn't automatically come to a person at a certain age,
it comes to a person when one wants to be mature.
In short,
maturity isn't gained with age,
It is gained upon choice.