Hard habit to break. I learned it so long ago too.

Haha I learned to type organically, and it was only in my mid-40s that I retrained myself to type the correct way. It took something like 40 hours of practice on keybr.com before I could get close enough to my regular typing speed, such that I could switch over to the 'correct' method without it impacting my work.

Retraining myself to stop doing double-spaces took maybe a week.