Character depth without a dark backstory/secrets?

[Clistenes]

Actually, I think creating a character with more normal, human motivations and backstory gives it more depth than the overused dark and troubled past does.

A 3.5 character I created was a natural medium (as represented by feats and flaws and a AL +1 template) and he had to travel to the mountains and train as a Shaman in order to control his powers despite being born in a culture that didn't have Shamans...

A 5e character I made belonged to the urban middle/high class (descended from a secondary branch of the low nobility and of merchants, his parents and grandparents were college lecturers, bureaucrats, scribes and guildsmen). He wished to be a Wizard, but he wasn't intelligent enough, so he settled for learning bardic arts while studing to become a bureaucrat, but during the war his family arranged for him to become the squire of a paladin, and he ended becoming a Paladin/Bard.

Another character was a Wizard had been passed around from relative to relative (he was an orphan) until he was taken in by his great grand-uncle, a famous Wizard, scholar and lecturer. He had low Charisma, low confidence, he was overcatious and he found it hard to form emotional connections, but he was fiercely loyal to his master and adopted father...