Hope the below helps you figure it out, AC81. See below the quote for my own opinion on Abilities:
Strength
1 (–5): Morbidly weak, has significant trouble lifting own limbs
2-3 (–4): Needs help to stand, can be knocked over by strong breezes
4-5 (–3): Knocked off balance by swinging something dense
6-7 (–2): Difficulty pushing an object of their weight
8-9 (–1): Has trouble even lifting heavy objects
10-11 (0): Can literally pull their own weight
12-13 (1): Carries heavy objects for short distances
14-15 (2): Visibly toned, throws small objects for long distances
16-17 (3): Carries heavy objects with one arm
18-19 (4): Can break objects like wood with bare hands
20-21 (5): Able to out-wrestle a work animal or catch a falling person
22-23 (6): Can pull very heavy objects at appreciable speeds
24-25 (7): Pinnacle of brawn, able to out-lift several people
Dexterity
1 (–5): Barely mobile, probably significantly paralyzed
2-3 (–4): Incapable of moving without noticeable effort or pain
4-5 (–3): Visible paralysis or physical difficulty
6-7 (–2): Significant klutz or very slow to react
8-9 (–1): Somewhat slow, occasionally trips over own feet
10-11 (0): Capable of usually catching a small tossed object
12-13 (1): Able to often hit large targets
14-15 (2): Can catch or dodge a medium-speed surprise projectile
16-17 (3): Able to often hit small targets
18-19 (4): Light on feet, able to often hit small moving targets
20-21 (5): Graceful, able to flow from one action into another easily
22-23 (6): Very graceful, capable of dodging a number of thrown objects
24-25 (7): Moves like water, reacting to all situations with almost no effort
Constitution
1 (–5): Minimal immune system, body reacts violently to anything foreign
2-3 (–4): Frail, suffers frequent broken bones
4-5 (–3): Bruises very easily, knocked out by a light punch
6-7 (–2): Unusually prone to disease and infection
8-9 (–1): Easily winded, incapable of a full day’s hard labor
10-11 (0): Occasionally contracts mild sicknesses
12-13 (1): Can take a few hits before being knocked unconscious
14-15 (2): Able to labor for twelve hours most days
16-17 (3): Easily shrugs off most illnesses
18-19 (4): Able to stay awake for days on end
20-21 (5): Very difficult to wear down, almost never feels fatigue
22-23 (6): Never gets sick, even to the most virulent diseases
24-25 (7): Tireless paragon of physical endurance
Intelligence
1 (–5): Animalistic, no longer capable of logic or reason
2-3 (–4): Barely able to function, very limited speech and knowledge
4-5 (–3): Often resorts to charades to express thoughts
6-7 (–2): Often misuses and mispronounces words
8-9 (–1): Has trouble following trains of thought, forgets most unimportant things
10-11 (0): Knows what they need to know to get by
12-13 (1): Knows a bit more than is necessary, fairly logical
14-15 (2): Able to do math or solve logic puzzles mentally with reasonable accuracy
16-17 (3): Fairly intelligent, able to understand new tasks quickly
18-19 (4): Very intelligent, may invent new processes or uses for knowledge
20-21 (5): Highly knowledgeable, probably the smartest person many people know
22-23 (6): Able to make Holmesian leaps of logic
24-25 (7): Famous as a sage and genius
Wisdom
1 (–5): Seemingly incapable of thought, barely aware
2-3 (–4): Rarely notices important or prominent items, people, or occurrences
4-5 (–3): Seemingly incapable of forethought
6-7 (–2): Often fails to exert common sense
8-9 (–1): Forgets or opts not to consider options before taking action
10-11 (0): Makes reasoned decisions most of the time
12-13 (1): Able to tell when a person is upset
14-15 (2): Can get hunches about a situation that doesn’t feel right
16-17 (3): Reads people and situations fairly well
18-19 (4): Often used as a source of wisdom or decider of actions
20-21 (5): Reads people and situations very well, almost unconsciously
22-23 (6): Can tell minute differences among many situations
24-25 (7): Nearly prescient, able to reason far beyond logic
Charisma
1 (–5): Barely conscious, probably acts heavily autistic
2-3 (–4): Minimal independent thought, relies heavily on others to think instead
4-5 (–3): Has trouble thinking of others as people
6-7 (–2): Terribly reticent, uninteresting, or rude
8-9 (–1): Something of a bore or makes people mildly uncomfortable
10-11 (0): Capable of polite conversation
12-13 (1): Mildly interesting, knows what to say to the right people
14-15 (2): Interesting, knows what to say to most people
16-17 (3): Popular, receives greetings and conversations on the street
18-19 (4): Immediately likeable by many people, subject of favorable talk
20-21 (5): Life of the party, able to keep people entertained for hours
22-23 (6): Immediately likeable by almost everybody
24-25 (7): Renowned for wit, personality, and/or looks
I feel it is impossible to actually RP Abilities as they are represented by a numerical number that can increase to god-like ability.
So what I do, when RPing my characters, through their entire life, is RP their Abilities
as they are at Character creation.
With an INT-based Character then, if I started her at 16 INT, she would be "16-17 (3): Fairly intelligent, able to understand new tasks quickly." If I made a Character starting at 18 INT, then she would be "18-19 (4): Very intelligent, may invent new processes or uses for knowledge." Now, some races can be started at Ability X at 20, which means, there is possibility for having a Character that I would RP as "20-21 (5): Highly knowledgeable, probably the smartest person many people know."
So why do I do this? Because 1) it makes my life easier, because trying to RP something I have no capacity to actually understand, is well...not my cup of tea; 2) I don't have to wait until Level 30 in order to "be the Character I want it to be"—they can be that over-analytical smarty-pants from day one, until Day of Death.
And do I honor the Sheet, when in reality, the INT does continue to climb? Yes, I do...by RPing the Character to have simply been training their natural abilities to the utmost potential possible. So, my initial INT 20 PC may reach INT 30 in their "lifetime of experience," but those last 30 points are really the lifetime of training and development, not any sort of actually brain size increase, or something like that.
What I wrote above, I believe, can be translated to any of the Abilities of a PC. And, can quickly give you a way to invest in the personality of the Character, instead of getting hung up on the "how the hellz does a super smart nerd wizard think?"
Cheers.
