Thankfullness Vs Selfishness
This is a good question and reflects your intelligence and sensitivity. God has created this world for a test whose reward is eternal blessings. Human beings willingly agreed to take this test. This is what God has told us. If one agrees with this divine scheme, the blessings difficulties, and disabilities all are for the test. Everyone will be answerable to God for whatever he is given and what is not. Those who lack something will not have to be answerable for that. Those who face difficulties will have the benefit of practicing Sabr and those who have something are in the test of Shukr. They will be asked how they dealt with the facilities they had.