What is this anecdote supposed to tell the OP? I can only assume that the intent is to imply a link between this man's advice and his wealth, but data isn't the plural of anecdote.
Well I'm just relaying the advice of a somewhat successful man, which I didn't take. But to expand I think what he meant was if you're confident that you can do it and you mean to do it, then don't halve the responsibility. Take it all.
I really don't agree. I'm pretty confident in my ability to do what I do, but having a cofounder has given me a useful critic (amongst other things). Having gone through this stuff, I would have wanted to have done it on my own. *
> just relaying the advice of a somewhat successful man
This is a fallacy. Unless it's backed up by really good reasoning, I wouldn't take someone's advice seriously _simply because_ s/he has been successful at _something_. There are too many factors at play and way too much context to make it meaningful unless it obviously translates to the situation at hand. I can't think of a plausible reason why having a business partner is, 100% of the time, a bad thing (which is what is suggested in this anecdote).
* caveats: "having a cofounder" is obviously not a panacea, and may not be a good thing if you don't have the right relationship (which seems fairly clear from the OP)
I'm not arguing. I'm "relaying". He's more successful than I am. He gave me the advice. Looking back I regret not taking it for a variety of reasons. Everybody's going to be different.