I guess I'm basing too much on the 4th ed website. According to the website, all classes except rangers and rogues get 4 skills, rangers get 5, and rogues get 6. Humans get an extra one. A skill roll is d20 + 1/2 character level + racial modifier + 5 if trained. So, even if you aren't trained in the skill, you still get half of your level added to your roll, even though you missing out on that extra +5. Hence, everyone gets better at all skills as they level. The clumsy fighter can still do cartwheels with enough levels under his belt, the frail wizard can run hurdles, etc.

After my last post, I saw exactly that! An aged man with a three foot long white beard and spectacles rushing down a 100 m dash, pole vaulting and swimming

Athletics is a bad example... none of it is trained-only (which is the only reason to select skills now)

No biggie. I shouldn't get upset when newer editions aren't as accommodating to my playstyle as older once were anyway :-p It isn't like I can't still do it with some house ruling.

If it turns out this is covered in the rules, I owe the system itself an apology.

The book has everyone with 3, rangers and rogues with 4.

There is another variable here which I should bring up. It's something I personally have a hard time accepting, but skill DCs are supposed to get harder as you progress as well. Hey! Don't shoot the messenger, but as I understand it, swinging from a chandelier might be DC 15 at tenth level and DC 25 at 20th.

only if it's a skill challenge :P

I do see where he's coming from though, our super wizard, despite rarely leaving his tower, is more street wise than the 20th level adventurer who's lived his life in back alleys.

As Acrobatic and Stealthy as our Rogue, and as Endurant that before said Fighter.
Easy way to word it, 'being high level makes you better'

Well, he has be adventureing for 30 levels (not just studying in his tower) getting better at all those things adventurers do. The XP difference between 20 and 30 is MONUMENTAL.

I understand that the wizard could become good at those things, I just don't like that the system is set up so that he automatically becomes better at them.