Aragorn's reluctancy, was it totally wrong?

[Tigerlily Gamgee]

Well, he knew that he was the heir, but perhaps he wanted to prove to himself that he was worthy of such a position before just claming it. In the books he camps outside the city and won't even enter it until he is king, no? I think he needed to be portrayed as being more humble about the position rather than power thirsy for it. It may have made him a less likeable character had he rallied people behind him, ridden off to Gondor, and thrown Denethor off the thrown just because his destiny said it was so.