how long until you perfected blind jumps?

Blind jumps: for example playing octaves while sight reading without looking

I feel like i spent months on practising these jumps, i prob have 90% accuracy but its so annoying when you miss.

is this normal or do you spent less time on it and perfected it? pls brag, i wanna know if i do smth wrong

every morning when i practise jumps , i feel like i have to start from the beginning especially on the right hand.

i practise these with tons of variation but it just doesnt stick