It's quite obvious that things that are more rare are easier to remember. But the way this works in poker is quite amazing, I think. That's because there are 2 factors instead of just 1 - value and suit. They both perfectly cooperate with the difficulty level of memorization within a 5 card poker hand.
So, when you are dealt 5 random cards from a 52 deck and asked to remember them (value and suit) for as long as you can, you can be sure that:
>>>The higher the hand strength (type), the longer time you'll be able to remember the cards.
T
J
Q
K
A
- You have to remember only 1 suit.
4
5
6
7
8
- You have to remember 1 suit and one value (top card).
A
A
A
A
6
- You have to remember one value + one value with suit (kicker).
7
7
7
K
K
- You have to remember one value with 3 suits (trips) + one value with 2 suits (pair).
K
J
9
6
2
- You have to remember five values and 1 suit.
7
8
9
T
J
- You have to remember five values with 5 suits.
4
4
4
8
A
- You have to remember one value with 3 suits (trips) + two values with 2 suits (kickers).
8
8
2
2
5
- You have to remember one value with 2 suits (pair) + one value with 2 suits (pair) + one value with suit (kicker).
Q
Q
2
5
9
- You have to remember one value with 2 suits (pair) + three values with 3 suits (kickers).
3
4
7
9
K
- You have to remember five values with 5 suits.
I'm not sure where this leads to, but it must lead somewhere...