St. Alphonsus - never occupied about matters more curious than useful

The Life of St. Alphonsus:

He was of middle size, with a rather large head, and of a fresh
complexion. He had a full forehead, pleasing azure blue eyes,
an aquiline nose, a small mouth and smiling lips. His
beard was thick and his hair black; he kept them short, 
and often cut them himself. He was short-sighted and
made use of glasses, but never in the pulpit or when 
he spoke to women. His voice was clear and sonorous;
however spacious the church might be, and however long
a mission might last, it never failed him, and it continued
thus until his last infirmities. He had an imposing mien;
his manners were grave and gracious at the same time.
His judgment was subtle arid penetrating; his memory
prompt and tenacious; and his mind precise and methodical.
He was of a passionate temper, but through virtue he
became a model of sweetness. His whole life was one
continual application ; but he was never occupied about 
indifferent things, nor even about matters which were more 
curious than useful. 

Reject all studies that are merely curious

Imitation of Christ:

vice of curiosity

human science exceedingly wearisome--St. Benedict Joseph Labre

St. Benedict Joseph Labre:

When he had attained to sixteen years of age, he entirely lost the pleasure which he had till then felt in learning Latin well ; it became on the contrary so distasteful to him, that he applied to it with less diligence, turning all his fervour towards the science of the saints....

Benedict now judged it a proper time to declare to him openly, but with modest respect, that he felt himself moved by God to other designs than to remain in the world, that the study of Latin had become exceedingly wearisome to him, and so would any other human science in comparison with the divine, which teaches us to know God and the best manner of securing the great affair of eternal salvation, which is common to all ; he manifested to him the sweet violence by which he felt himself drawn by Almighty God to a total abandonment of the world, in order to attend to God alone, and to eternal salvation in a cloister, which should be the most austere of any, and this he thought was that of La Trappe.

From that time he knew that study did not suit Benedict, but rather the science of the saints, and that the Almighty desired another manner of proceeding from him, and knowing him to be not only blameless of every sort of fault, but endowed with even heroic virtue, he could not call blameable that disrelish which he showed for every other study. Here let a little digression be permitted to me, in order to defend Benedict from the accusation which some inexperienced person might fix upon him, of being guilty of a fault by this disrelish for study. Having related in the preceding chapters the little application of Benedict in learning the sciences, and the reproofs by which his uncle and others mortified him, any one might think him guilty of disobedience. But what disobedience, what fault can there be, if it were all the dispensation of Almighty God, who having other designs upon him, guided him, inciting him by His sweet attractions, to follow that path which would make him a particular model of sanctity? God willed him to be a perfect anchorite in the midst of the world, not a learned man, an example, not a preacher, which, according to St. Thomas, is more efficacious in persuading men than words, "Homines magis exemplo trahuntur, quam verbis." God willing him to be an anchorite, what necessity had he for study and knowledge ? How could they have agreed with the neglected, humble, penitent, and solitary state, in which God willed him? St. Theresa likewise forbade her Carmelite nuns to study Latin, or anything little suited to their state, and she declared herself desirous, in a letter written to the prioress of Seville, that her daughters living entirely apart from the world, should have the holy ambition of appearing simple and ignorant, as many saints have done, rather than of being female rhetoricians. Thus after some years, when Benedict knew as much of Latin as sufficed to understand the sense, and to nourish his soul with the frequent reading of the Holy Scriptures.

despising useless knowledge

[St. Basil the Great] contented himself with learning the
general principles of geometry, medicine, and the like sciences,
rightly judging such an insight into all the arts of extreme use
to a person who would excel in any of them, but despising whatever
seemed useless to one who had devoted himself solely to
religion and piety. In checking thus his curiosity and natural
thirst after knowledge, according to the excellent reflection of
St. Gregory Nazianzen, he was not less admirable for what he
neglected in the sciences than for what he had learned. Source