Our Gemara on Amud Aleph discusses the status of a promissory note that was lost and found. Ordinarily, these notes with signatures of witnesses have a presumption of validity. However, since this document was dropped, that in and of itself weakens its legitimacy. (Perhaps the loan was canceled or not even enacted, and it was discarded and not lost at all.) Therefore, if one finds this document, he may not be able to return it to the lender, as perhaps it is not valid and would cause loss to the putative borrower.
Mei Shiloach (Commentary on Bava Metzia) wonders why a promissory note loses validity when dropped, while an object is returned to the owner who provides evidence of ownership (a contract inherently has evidence of ownership since the principals are named). He suggests a metaphysical answer. Objects and utensils provide utility to their owners, and thus we might surmise that they providential lost use of their object for a period of time (presumably as some kind of suffering or atonement.). Now that the object is found, the period of time has ended, and God wants him to have his object back. However, a promissory note has no inherent utility or value, and if it was lost, we might presume that providence indicates that perhaps it should remain lost, as it might be a false document.
I am not sure why the Mei Shiloach doesn’t consider that perhaps it was providential that the person experienced the frustration and temporary loss of ability to collect the loan. Then we might equally assume that the finding of the contract represents an end to that previous loss, much as a found object reflects God’s granting its return. I believe the answer is that it is about the preponderance of evidence and likelihood. Since, there are many ways to have financial loss or gain and frustrations, there is no particular providential need to lose the document, as it is only one form of financial loss or gain. If the contract was lost this seems to more firmly indicate that it is not a valid document, and was taken from the wrongful owner’s hand via a providentially arranged loss. However, each object has its own specific purpose, and so its loss is presumed to indicate God’s will that he lose it, as well as it being found indicating God's will for it to be found.
Theologically speaking, to what extent shall one assume that minor daily losses or gains are a result of God’s direct will? The Gemara (Arachin 16b) delves into this matter:
The Gemara asks: Until where is the minimum limit of suffering? What is the least amount of pain that is included in the definition of suffering?
Rav Ḥisda, and some say it was Rabbi Yitzḥak, and some say it was taught in a baraisa: Even if one reached his hand into his pocket to take out three coins, but two coins came up in his hand, it is considered a form of suffering.
The Gemara indicates even a small amount of suffering still is considered a form of atonement. Even so, there are limits, as it goes on to say:
This is only in a case where one reached into his pocket to take three coins, and two coins came up in his hand. But if he reached into his pocket to take two, and instead three coins came up in his hand, this is not considered to be suffering, as it is not an exertion to drop the extra coin back into his pocket.
At first glance, this implies that providence causes even these minor losses in order to have suffering and atonement. This seems to be the way the majority of commentaries understand this Gemara. Strictly speaking, we might argue that the Gemara is only advising that suffering, even if comes incidentally, should be utilized and viewed as an experience to achieve atonement. While the Maharal doesn’t take this position specifically, the following idea of his allows room for this to be theologically valid. He explains (Nesivos Olam, Nesiv Hayisurin 3.3, I paraphrase):
Even the minor inconveniences and losses, when taken with the proper mindset, promote letting go of attachment to material matters. These daily vicissitudes can be seen as reminders that we ought not overvalue our urge for comfort, as this leads to complacency and detachment from the spiritual.
Regardless, Judaism has a specific philosophy as to the meaning of the small losses in life, which is to take them as opportunities to be humbled, and reflect on one’s sins and reasons why such a loss might be deserved. Ramban (Shaar Hagemul) speaks of this, and says that even the righteous will go through these typical frustrations and losses in the course of life in order to atone for minor sins. Based on a Midrash, Ohel Yaakov (Tazria 5) goes further to imply that God even allows the minor suffering to qualify and atone for sins that are much greater. Noda BeYehuda (Teshuvos OC I:35) also seems to hold that the function of these minor problems are to provide easier atonement for what ordinarily should incur greater punishment.
Psychologically speaking, a sense of entitlement and excessive attachment or expectations leads to suffering and disappointment. We may wish and hope for many things, and work diligently to succeed, but it is healthy to consider that we may not always get what we want. Life, for all its wonders and gifts, requires mortality and physical experience. It is impossible to be physical and not suffer losses and entropy. This is the price we pay to live. Light without darkness is the same as darkness, since it is impossible to see without contrast. So too, life without loss and suffering Ii’s impossible.