Furmyr says:
As for why an experienced soldier is level 1. I was thinking maybe he took damage in action, and his body is hurting. Leveling up for him is actually the body getting back into its old shape.
Mmm. The problem is that the game's system doesn't really work in such a way as to take this idea into account. For example, if your character is "experienced", he should, theoretically, have at least one skill higher than level 3 or have more skills at this point, but beginning PCs should all start at roughly the same "power level" eg number of skills constrained by points to buy them with and the arbitrary, but still sensible, rule about no beginning PC starting with more than three levels in any specialization.
Your idea is, of course, imaginary "fluff" for your PC's background, but it might create problems later that I won't want to deal with. Maybe you could explain why your heart is seemingly set on this idea for your PC . . . .
Now, all this being said, there is, sort of, a way to come close to this idea of yours, taking into account your new idea about healing an old wound: take the flaw "Old Injury" at a high point value, say six (the max) and put those extra points places that give you more skills at level 3 or just give you more skills overall.
Your age could also start out higher than the assumed starting age for PCs (ie 25) to suggest someone who's been around for a while, but I don't think your PC should be 40 or older (that would mean giving your PC bonuses in INT and PER with no corresponding penalties).