Let's assume one of your siblings came to you asking for an urgent money to buy a pen. Then you ask him what he wanted to use it for, and he said he needed it in completing his assignment. As a good sibling that you are, you gave him the money. He bought the pen and completed the assignment.
This kind of scenario repeats itself every day with different kinds of request from your sibling.

To your surprise,he never said, "thank you". He always leaves the house without even saying, "thank you for yesterday". 

At this point, what would you have done? 

If it were me, I would wonder if what I have been doing for him was worth it. How would I be catering for your needs and you wouldn't be grateful for it?
I would patiently await that next time he would request for something.

Then boom! He would request for something again and I would tell him," The ones I've been giving you did you show your gratitude? Have you ever thank me for giving you what you need? I don't have anything to give you."

I know this is exactly what you will do( you can even do more than this).

The older sibling represent "God" and the younger one represent "you"(we, human beings). That is how God does whenever we refused to say "thank you" to Him. A Yoruba proverb says, "Bi a ba dupẹ ore ana, a o ri omiran gba( If we appreciate yesterday's help, we will receive another one)."

Stop comparing and complaining about your status.
At all times and for everything, give thanks to God.

Happy New Month.