That's a problem with the skill system. The "Profession" Skill is a really not a single Skill at all, but a group of related Skills used under similar circumstances. I included "Rope Use" at less than Profession (Sailor) because the skills he acquired as a sailor transfer over to other situations where ropes & knots are used (such as mountain climbing). He has no direct experience at climbing mountains, but if the Ranger hands him a coil of rope and says "Tie me some harnesses", the Sailor can figure it out pretty quickly (faster than the Fighter with the Noble background, at any rate).
That's not how I read it. A 1st level PC is someone who has just starting
adventuring, as opposed to a normal, non-adventurous life. I recall an AD&D 2e campaign where we all rolled up 1st level characters, and my buddy made a 1st level human Wizard who was in his 60's (for the age bonus to Int, obviously

). His character history was that he had been a local herbalist and hedge wizard (0th level, no formal training) for most of his life, but had come across a "real" spellbook and collection of magical treatises late in life. The DM just gave him a couple extra NWP; the AD&D 2e equivalent of my Background house rules. If that had been a 3e campaign it wouldn't have been fair to force him to be a 3rd-5th level Expert however (why all the HP?), when the rest of us would be leveling up so much faster, but it also wouldn't have made any sense if he didn't have some of the appropriate skills.
This. right. here. is the down-side of the evolution from 1e to 3e. The 3e rules have attempted to create "universal mechanics" for all PC's (and it pretty much has), but the Skill System and the Multi-classing rules simply do not allow you to make a PC with certain backgrounds (without shooting yourself in the foot, big time). For purposes of making PC's with interesting backgrounds, the RAW only works so long as you don't try to multi-class NPC and PC classes. Someone who's been at sea for 20 years probably can be accurately modeled as a 7-10th level Commoner (for the crew) or Expert/Aristocrat (for the officers), but that should not be a penalty for deciding later in life to go adventuring as a Fighter or Wizard.
An alternative to my Background rules would be to allow "Free" multi-classing between PC classes and NPC classes. The NPC classes would be the exception to the rule that you add all your class levels together to determine "Character level." That way you could be a 4th level Commoner (Farmer, Sailor, whatever) and a 1st level Adventurer. To implement this you'd probably have to tweak the rules for HD, HP and Saves (etc.), but this is an easy problem to fix.