Immersing Oneself
noun, verbal noun
All the extra things die in the head when one is immersing oneself in one thing. That way, the thing they're focusing on is the only thing in their brain.
没頭 is a relatively formal word that means being deeply absorbed or engrossed in something. It's often positive and describes a state where someone is so focused on an activity they lose track of time or forget about everything else.
This is a jukugo word that uses the on'yomi readings of the kanji. You've learned them both already, so you should be able to read this word.
好きなことに没頭できるなんて、幸せですね。
If you can immerse yourself in things you like, you'll be happy.