Intelligence, being smart, or being highly skilled are often far less important than putting in effort. I'm a strong believer that the moral of the fable of
"The Tortoise and the Hare" is usually taught incorrectly (or perhaps more accurately
incompletely) to children.
The story, in short for those who may not know it goes as follows:
Now, as I've always heard it taught, the moral of this story is
"slow but steady wins the race" -- which is of course not true in and of itself -- had the hare not stopped to take a nap there is no way the "slow but steady" approach of the tortoise would have resulted in victory.
A better lesson to take away from the story might be
"don't be lazy" ; just because you have (or think you have) a strong natural ability in an area doesn't mean you will automatically succeed, you still need to put in the effort and
apply that ability to find success. The other obvious lesson is that being less capable in a certain area does not automatically mean failure; if you apply yourself and put in the work you can often still succeed. Furthermore, had the tortoise had access to and foresight to use a horse to carry him through the race he may even have been able to beat the hare even without the nap, showing that where someone is less able it can be a good idea to find the help of someone who can contribute more strongly in that area.
Also, as others have already mentioned (putting aside highly unusual circumstances like a mental or physical disability preventing or restricting use of certain abilities) skills are learned and up to certain limitations can be improved with study and practice; there
is a limit to how fast a human can run, but any able-bodied person who takes to training and running regularly will end up able to run faster and for longer than they could before they started training. The same applies to social skills, business management, and even things like memory. If you're lacking in social skills you should get out there and
practice.
Lastly, in the story from the original post, I believe John has an additional advantage that has not yet been commented on in great detail: John appears to accept that he will make mistakes, and is willing to
try anyway, while from the sounds of it I suspect the highly-skilled Henry might have a bit of a fear of embarrassment and/or public humiliation and put far more effort into trying to do things right the first time and avoid mistakes. Mistakes are an excellent learning opportunity, and whilst they can sometimes be costly and should be avoided where easily foreseen they should not be something to fear, and should certainly not stop you from trying things. If you have trouble training your social skills because you're afraid of embarrassment you need to let that go and force yourself to do it anyway -- if you're just chatting to people in lines at shops, whilst on the bus, in bars or any similar situations then what does it matter if those people form a bad opinion of you? You're unlikely to see them again anyway, and if you do the slip-up may well be forgotten anyway, or might be written off as the product of a bad day if your social skills have since improved. Get out there and
try, or you'll never get better!
If you're finding you're stuck without conversation try asking questions about the other person and then responding to what they say; people usually like to talk about themselves, and as long as you aren't constantly pestering them asking a couple of questions can be a good way to strike up conversation -- perhaps they'll say something that will allow you to segue to one of the alphabet stories suggested earlier in the topic. Asking questions is simple --
"that's a nice sweater, where did you get it?" [...] "Oh, what a bargain, I might have to check out that sale. I once got a <insert popular brand here> shirt 50% off because..."
or
"I see you've changed your hair, I like the new colour, when did you get that done?"
or
"So where is that accent from anyway, I take it you're not originally from the area?"
or if you're trying to start up a conversation with an unfamiliar woman (or man), even the lamest of lines will work as long as you deliver it confidently and with a smile -- remember, you're just talking to them, it doesn't necessarily have to lead to anything further -- you can decide to pursue that if the conversation is going well and you're interested:
"Do you know how much a polar-bear weighs?" [...] "Just enough to break the ice, I'm Henry."
With a little practice and a few mistakes you'll quickly learn what usually works and what usually doesn't.