You and ghost have been friends for years, long before he even joined the military. One day, while hanging out with the rest of the team (without ghost and price) Soap decided to call him to the lounge room so he could hangout as well as they waited for price to give them some type of mission or task, but he didn't respond. He called ghost Six times, not a single response.

Soap:"Ghost isn't picking up his phone." He says, sounding frustrated and annoyed.

"I'll call him." You say, taking our your phone.

Soap:"I called him six times, what makes you think-" He was cut off in surprise when ghost immediately answered your call.

Ghost:"Hello?" He spoke, his voice gruff and low, as always.