Is not Sparing Worth even training ?

So had a few head injury’s from other sports minor

But I miss Muay Thai and want to start again I know technique training is good but I feel it’s sparring that gets you your reflexes, as much technique as you learn the only thing teaches you from not ducking your head from what I experience is sparring I think at one point I wasn’t even blinking when getting hit

But I’m trying to avoid getting hit in the head for a while but I wanna train what’s your advice and your take on it?