The video has DBS spoilers and Dragon Ball Super: Broly spoilers as well so be warned!
Here is a list of the mysteries in the video above:
1: The wish made at the end of DBS: Broly
2: Lunch/Launch's disappearance
3: Goku's mind reading technique that was never used again
4: How did Goku really escape Namek
5: What did Captain Ginyu look like originally
6: Kaio-ken only taught to Goku
7: The moon reappeared again, and again
8: Vegeta's mother
9: Tarble's tail in question
10: Goku's solo training in Dragon Ball
11: Zamasu started his 0 mortals plan in the future for no reason
12: Beerus said he wiped out the dinosaurs yet they were still on earth throughout the series
13: Only heroes can keep their bodies in the after life yet plenty villains and none-heroes have kept their bodies
14: Half saiyan tail mystery
15: Goten and Trunks aren't getting older
16: Energy breaking the universe/reality
17: Two unknown saiyans lived on after Planet Vegeta was destroyed but were never shown
18: Master Roshi's long, long life (immortality)
19: Android 16 was never brought back
20: Everyone knows how powerful the Z fighters are - yet they forgot?
2: Lunch/Launch's disappearance
3: Goku's mind reading technique that was never used again
4: How did Goku really escape Namek
5: What did Captain Ginyu look like originally
6: Kaio-ken only taught to Goku
7: The moon reappeared again, and again
8: Vegeta's mother
9: Tarble's tail in question
10: Goku's solo training in Dragon Ball
11: Zamasu started his 0 mortals plan in the future for no reason
12: Beerus said he wiped out the dinosaurs yet they were still on earth throughout the series
13: Only heroes can keep their bodies in the after life yet plenty villains and none-heroes have kept their bodies
14: Half saiyan tail mystery
15: Goten and Trunks aren't getting older
16: Energy breaking the universe/reality
17: Two unknown saiyans lived on after Planet Vegeta was destroyed but were never shown
18: Master Roshi's long, long life (immortality)
19: Android 16 was never brought back
20: Everyone knows how powerful the Z fighters are - yet they forgot?
Feel free to talk on any one of the mysteries listed or making a thread dedicated to one of them if you have a lot to say.