There's a flashback sequence at the start of The Last Crusade that shows a young Indiana Jones (played by River Phoenix) on a trip with a scout troop where he tries to recover a priceless artifact ...

The TV series The Young Indiana Jones Chronicles showed just how much adventure has been in Indy’s blood since childhood, and one of its highlight episodes is “Treasure of the Peacock’s Eye.” ...

We won’t be including the Young Indiana Jones Chronicles here, since there is a lot of dispute about if the TV show is canon, primarily due to a lot of inconsistencies between it and the movies.