Remnant: From the Ashes takes place in a universe where our common, everyday items - such as Pocket Watch - are extraordinarily rare, and therefore odd by default. Here, you'll learn where to find Pocket Watch and what to do with it.
Many of these items come from weird interactions with equally weird characters, and the Old Man who gives you the Pocket Watch is no different. Your first step in getting this item is to find the Old Man singing in a crashed helicopter, on Earth.
Remnant: From the Ashes Pocket Watch
More precisely, you need to look for the crashed helicopter by a randomly placed crossroads on Earth, and then you're going to have to exhaust all of the dialogue options with the Old Man before he awards you the Pocket Watch for being such a good listener. Be warned, however, as there's a lot of dialogue to go through.
After you've received your Pocket Watch, you're going to need to find Brabus in Rhom. This boss encounter can progress in a few different ways, and if you want to unlock the special Bandit Set of armor, you're going to have to offer the Pocket Watch to Brabus. It's simple as that, but moderately time-consuming, if you consider all the steps included in unlocking this armor.
We've got no shortage of handy Remnant guides here at Game Watcher. For example, you can learn what to do with the strange Tarnished Ring, and how to find the Twisted Mask. Don't forget to unlock the Chicago Typewriter, either.