Actually, technically, there is no key of D#. It'd be Eb. Comprised of Eb, G, Bb. (The 1-3-5 of the Eb scale. Reference back to the "counting" method and the 'wwhwwwh' scale structure I shared in that PM.)

Familiarize yourself with this.



C is "neutral". As you move left, you add a flat. As you move right, you add a sharp.

Also note that as you move left you move from the root note to the 4th of that scale. As you move right you move from the root note to the 5th of that scale.

When you hear that the progression is "1-4-5" from whatever your start key is, 4 is one to the left, 5 is one to the right.

The green letters in the inner circle are the 6th step of the scale, called the relative minor. The famous "Don't Stop Believing" chord riff is 1-5-6m-4, lifted from Pachelbel's Canon in D. Using that Circle of 5ths chart you can wing that song in any key. Or play at any blues jam, which are mostly going to be some variation of 1-4-5 with that occasional 6m tossed in.

It's all about repetitions. The more golf balls you hit or rounds you fire, the better you become at whatever the skill is. If you want it, you'll get there.