be elderly
If by saying "be elderly" you mean "being cognitively compromised by natural aging", then sure I can see that, but usually those that have massed that level of wealth have people to shield them from these kind of scams. Still, on this list this one I agree is the most likely.
have no human contact
I seems like a very rare use case for someone to have $300,000 in liquid assets/cash that would not have human contact. I'm not saying its impossible, but it seems like the confluence of those two things would be extremely rare.
someone acts like they really love you
I would think someone asking you for $300,000 would be a sign they don't really love you.