There is more to hearing chords than just being able to pick out the notes. Ideally, you’ll want to be able to create your own chord progressions.
A chord progression is more than just stringing a few chords together. There is a lot of rhythm involved.
And that rhythm is created with your strumming.
Being able to mimic the chords and progressions of musicians you like will go a long way to helping you develop your own style.
To that end, being able to tell the difference between a down strum and an up strum will help you immensely.
A down strum tends to sound heavier than an up strum. Listen closely to the examples and see if you can tell the difference.
Play in the Key of YOU!