A young man who has no relish for the diversions and amusements that are natural and suitable to his age, who talks of nothing but his book or his business, is disliked as formal and pedantic; and we give him no credit for his abstinence even from improper indulgences, to which he seems to have so little inclination.
The principle of self-estimation may be too high, and it may likewise be too low.
 Adam Smith, The Theory of Moral Sentiments (1759). copy citation

Context

“it is justly blamed as excessive, and as hurtful both to the individual and to the society. In the greater part of such cases, however, what is chiefly to be found fault with is, not so much the strength of the propensity to joy as the weakness of the sense of propriety and duty. A young man who has no relish for the diversions and amusements that are natural and suitable to his age, who talks of nothing but his book or his business, is disliked as formal and pedantic; and we give him no credit for his abstinence even from improper indulgences, to which he seems to have so little inclination. The principle of self-estimation may be too high, and it may likewise be too low. It is so very agreeable to think highly, and so very disagreeable to think meanly of ourselves, that, to the person himself, it cannot well be doubted, but that some degree of excess must be much less disagreeable than any degree of defect.” source