[rando231]

You will probably learn many languages in your career. Most of the understanding you'll gain will apply across languages, so I wouldn't worry about it being a waste of time.

Learning Java should force you to understand object oriented design, as it is hard to do anything well in Java without it (though some try). While there are signs that OO's domination is nearing an end, there are reams of code out there that require a good understanding of it.