That everyone's mind wanders, including meditation masters' and probably even the Dalai Lama's. The only difference is, they've learned to accept that it will happen. When you notice your brain drifting, just bring it back without mentally "telling yourself off" or feeling like you're not doing this well or whatever. Your mind drifting is a built-in feature. You CAN'T make it stop. You can only reduce it, and that's a forever process.
I try to bring back my thoughts to the my breathing or one particular sound in the room to stop mind chattering thoughts….. It is difficult but definitely possible and I am getting nearer and nearer to it
concentrate on your breath. Focus on something. Your heart center. Your third eye. A candle flame. Say a mantra in your head. Sooo Humm. Inhale the world So. Exhale the word Hum. soooo hmmm. Try these 3. Sometimes I do all 3 together