Alright, I understand the concept of performing RCs during the day to hopefully perform them during a dream, with the hopes that they will induce a LD. The RCs I like best are: trying to breathe through a pinched nose, finger into palm, and checking the time.

As I understand it, it's important to perform more than one kind of RC, just in case one fails in a dream. That way the other(s) will hopefully not. My question is specifically about the time checking RC. In a dream, it's said that if you look at a clock or your watch, and then look back, the time will be different. This is supposed to be due to our subconscious short-term memory not being so good or something like that. (This is also supposed to be true for reading text and then re-reading it)

But what good is it going to be if your short term memory is poor, and you look at the time and it's different than 10 seconds earlier? Won't you simply forget what the previous time was and the RC will fail anyway? How is the time checking RC supposed to help you in aiding a LD?