It may be that you just start with one hog, who happens to have significant distinguishing features. That’s how I started. There was one hog who I just couldn’t help recognising. She was around for about 5 years and it was always a joy seeing her arriving after hibernation.
She was very recognisable either in real time or on the camera, Then I realised I was starting to recognise others and gradually, at that time, had 12 different adult hedgehogs which I could recognise fairly easily. Needless to say they didn’t all visit at the same time, nor did all of them visit every night. It was the females who were the most loyal patrons of my hog restaurant. The males came and went a bit. But by recognising them and keeping meticulous notes, I was able to observe a lot of their behaviour. Mostly from watching in real time.
These days there seem, in general, to be fewer hogs around, so theoretically it should be easier to recognise them, if that is what you choose to do. Sadly when other people artificially mark the hogs it makes it a bit more difficult to identify them naturally, but it’s usually still possible.