
In the modern world, Mr. Twain’s humorous remarks have sadly become the normality of society. There are those who seek power, those who have power, and those whose rights are trampled by the first two.
Of course, BIBLICALLY the chief end of man can be summed up differently. Here the Westminster Catechism does an excellent Job:

Here is an extract from Thomas Watson’s Body of Divinity on the subject that I hope you find helpful. Watson addresses sub-subjects like: What is Glorifying, Why Glorify, and How may we glorify. Thomas notes strongly that all are pre-ludes to enjoyment, and the last time I checked everyone even the fools that Mark Twain was making fun of seeks enjoyment.
Pray for Grace to Assist you so that you may do your Duty Always and Everywhere