Reborn in the 80s: My Whole Family Secretly Hears My Thoughts and Goes Wild with Success!

We talked a little more until I could move. It was like my energy was drained to zero. I thought of something and called up my status. Like I thought, my MP went down a lot. It's now at 5/20 (+15). I wonder how this +15 is calculated. Maby I normally have only 5 maximum and the addition of 15 brings it to 20?