Eruvin 54b, Rashi: If one learns Chavilos (large amounts) at a time (without time to review properly), his learning will diminish (he will forget). If he learns small amounts at a time, it will increase.

Malbim: Also one who has great wealth, if he pursues folly, his wealth will decrease. Wealth needs efforts and supervision to increase it. If the owner will pursue folly, he will scatter (squander) the wealth and not increase it. It will decrease every time [he uses it], until it is finished. Even one who does not have wealth, but he strives and gathers little by little with his toil, he will increase and come to great wealth.

Malbim (according to Mashal): Even a great Chacham who gathered much Chachmah, if he will pursue folly, his wealth will decrease and he will forget his Torah. One who learns and strives to increase his Chachmah each day, it will increase, and in the end he will become a Chacham.