This isn't likely to be satisfactory, but I am tempted to suggest that we might sort of parallel the view that DeWitt suggested - that "life" rather than "pleasure" was Epicurus' greatest good. We might observe that from an Epicurean perspective the meaning of "pursuing pleasure and avoiding pain" comes down to a proper perspective on the verb "to live!"
Nope, nope, nope. (Another broken record of mine!)
Life *cannot* be the greatest good in the philosophical sense. Sure, life is good compared to the alternative, of course. But the "greatest good" is "that to which everything else points." The greatest good "in the opinion of all philosophers must needs be such that we are bound to test all things by it, but the standard itself by nothing." DeWitt's argument, as I remember, hinges on Latin not having a definite article ![]()
That said, I generally agree with your "pursuing pleasure and avoiding pain" comes down to a proper perspective on the verb "to live!" That "proper perspective" includes (but is not exclusive to) removing those fears, anxieties, empty beliefs, etc., that stand in the way of experience life as pleasurable.