Before wrestling with the angel of Eiasav, Yaakov "was left alone" (Bereishis 32:25). The Talmud (Chulin 91a) understands the verse to not only provide the environment and arena for Yaakov to be attacked, but also to address why he was alone. The word levado - alone is understood to include lechado, for his small jars and lesser important property, as the Torah previously informs us that he transported his possessions to the other side of the stream. Yaakov went back to retrieve pachim kitanim - incidentals. At first glance it seems most challenging to understand why Yaakov put himself at risk of being mugged? Rabbi Elazar explains that regarding the righteous, "their property is most precious to them for they do not engage in thievery".
Rav Yosef Salant zt"l in his B'ear Yosef offers the following keen insight: the Talmud (Yuma 38a-b) teaches in the name of Ben Zoma, "one's livelihood and position in life is destined with incredible precision On High. A person cannot encroach upon what has been designated for the next one, and the reign of one King cannot usurp nor encroach the reign of his predecessor even a hairsbreadth". Hashem thus gives each person what they need, when they need it. Therefore, everything that one is given is to help him fulfill his unique function and destiny in this world. Similarly, the Ohr HaChaim explains the verse, "when you lend money to My people, to the poor person who is with you" (Shemos 22:24) to mean that Hashem entrusted you with additional money to lend to the poor, or most specifically, Hashem gave you what the poor individual needs, so that you have the opportunity to give. The concept of hashgasha pratis - Divine providence is thus at the crux of this matter, and Yaakov is teaching how everything is to be appreciated, evaluated, and ultimately utilized in a productive fashion. There is no such thing as pachim ketanim, incidentals that are unnecessary; if G-d has given it to a person, it is to be used wisely.
There is a delicious Medrash that substantiates this lesson. The Yalkut Shimoni (Rus 607) relates that after a pious man lost his fortune and while working as a day laborer, Eliyanhu Hanavi appeared to him and offered him six good years of plenty. He was to choose if he wanted them now or at the end of his life, ensuring that he would not have to worry in his retirement years. He consulted with his intelligent wife, who advised to take the good years immediately, and miraculously their children found a treasure to maintain them comfortably for six years. His wife of sterling character said that once Hashem has shined his countenance upon them, they should share their wealth with others, perhaps He would extend their good fortune. She had her child transcribe daily their charitable acts and beneficence. At the end of six years, Eliyahu came and announced that the Divine infusion was over, and he came to retrieve the remaining monies. The man said, "as I took the money based upon the counsel of my wife, I will only return the balance with her counsel." Her response was to tell Eliyahu that if he has found more deserving individuals to entrust the money, then understandably take it. Thereupon, Hashem evaluated their acts of kindness and showered them with more blessings, enabling them to do more kindness.
I believe the lesson that Yaakov is teaching regarding actualizing potentials is not only to be understood regarding one's material possessions, but indeed regarding all virtues and characteristics that each and every individual is endowed with. On the verse "let us make man" (Bereishis 1:26) the commentaries explain that Hashem said, I will take from all the creations, from all the creatures, and incorporate the unique yet diversified qualities of each, and infuse them into man. Each person is different in their specific mix of the above traits. As the Yiddish expression goes, no one has it all. However, what you do have, don't squander or allow to remain unused or misused.
One who is blessed with more wisdom and the ability to discern and analyze dare not waste and allow to lie dormant his intellectual abilities. Similarly with health, one must appreciate this gift and nurture G-d's gift of health and even one's physical appearance. (On a personal note, I encouraged my young children to brush their teeth, by reminding them to brush Hashem's teeth). Courage, leadership and strength are among the many qualities that pachim ketanim teaches us to be careful not to waste.
Interestingly, Rabbi Elazar said that the righteous are careful with their possessions, as they do not engage in theft. I would like to suggest an additional explanation. The Vilna Gaon, as cited at the end of Maalas HaTorah written by his brother Reb Avraham, commenting on the phrase "v'sain chelkainu b'sorasecha - grant our share in your Torah", notes that as each person has their specific tafkid-purpose and function in this world, Hashem endows them with the necessary qualities and virtues to fulfill that tafkid. At the conclusion of Yom Kippur, in the Neilah service we ask for forgiveness, "l'maan nechdal m'oshek ya-deinu - so that we will withdraw from the theft in our hands", and Rav Soloveitchik zt"l suggested that indeed at the core of all sins is theft, namely misusing Hashem's gifts to us, in a way that He never intended. Similarly, Yaakov's returning for pachim ketanim demonstrates that not actualizing our abilities and potential is also a form thievery, having received God's gifts but failed to use them to their fullest.