I am discovering who I am and am connecting more with G-d but I always seem to have "aha" moments where everything seems to make sense at night. I go through the day with my mind racing and then at night when I lay in bed I figure out what it is that will help me connect to G-d on a deeper level and live my life in a better way. I wanted to know if there are any sources that talk about deeper thoughts at night. It might help me discover what it is that is bugging me before it consumes my day. I want to understand what others have already discovered without struggling. I want to be at peace and have my joy returned throughout the day.
Not sure if this quite what you’re looking for, but Maimonides (Mishneh Torah, Hilchot Talmud Torah 3:13) writes:
אף על פי שמצוה ללמוד ביום ובלילה אין אדם למד רוב חכמתו אלא בלילה לפיכך מי שרצה לזכות בכתר התורה יזהר בכל לילותיו ולא יאבד אפילו אחד מהן בשינה ואכילה ושתיה ושיחה וכיוצא בהן אלא בתלמוד תורה ודברי חכמה אמרו חכמים אין רנה של תורה אלא בלילה שנאמר קומי רוני בלילה וכל העוסק בתורה בלילה חוט של חסד נמשך עליו ביום שנאמר יומם יצוה ה׳ חסדו ובלילה שירה עמי תפלה לאל חיי וכל בית שאין נשמעים בו דברי תורה בלילה אש אוכלתו שנאמר כל חשך טמון לצפוניו תאכלהו אש לא נופח
Even though it is a mitzvah to study during the day and at night, it is only at night that a person acquires most of his wisdom. Therefore, a person who desires to merit the crown of Torah should be careful with all his nights, not giving up even one to sleep, eating, drinking, talk, or the like. Rather, [they should be devoted to] the study of Torah and the words of wisdom.
Our Sages declared: "The song of Torah can [be heard] only at night, as [Eichah 2:19] states: 'Arise, sing out at night...’“ Whoever occupies himself with Torah study at night will have a strand of [Divine] favor extended over him during the day, as [implied by Psalms 42:9]: "During the day, God ordains His kindness and, at night, His song is with me, a prayer to the living God."
[In contrast], any house in which the words of Torah cannot be heard at night will be consumed by fire, as [implied by Job 20:26]: "All the darkness is hidden away from His treasures; a fire that need not be blown will consume him."
Apparently, Torah and wisdom is especially allocated to the nighttime hours.
Following on from @Alex's train of thought, there are other sources that point specifically to the merits of learning at night and the clarity of thought during this period.
The Gemara in Tamid 32b writes:
תנא רבי חייא כל העוסק בתורה בלילה שכינה כנגדו שנאמר (איכה ב יט) קומי רוני בלילה לראש אשמורות שפכי כמים לבך נכח פני ה
Rabbi Chiya taught: With regard to anyone who occupies himself with Torah at night, the Divine Presence is across from him, as it is stated: “Arise, cry out in the night, at the beginning of the watches; pour out your heart like water before the face of the Lord, lift up your hands toward Him” (Eicha 2:19)
So it would seem at night, Torah thoughts have Divine inspiration.
This website writes that the Lubavitcher Rebbe in Likkutei Sichos Vol. 34 p.43 also notes the effectiveness of night:
Although it is a Mitzvah to learn Torah both by day and night, most of one’s wisdom is attained specifically through learning Torah at night. [This is due to several factors: 1) At night one is able to learn Torah in tranquillity without disturbances. 2) At night, there is a special Segula that the quality of one’s attachment to Hashem through learning Torah is greater than the quality of attachment experienced during the day’s learning.]
Perhaps this is why it writes in Vayikra Rabba 19:
רַבִּי יוֹחָנָן אוֹמֵר אֵין רִנָּה שֶׁל תּוֹרָה אֶלָּא בַּלַּיְלָה
Rabbi Yochanan says there is only joy of Torah at night.