Why on earth would you need to learn so many languages for a single startup idea?
I think the question you should be asking yourself is this "Do I want to be a brilliant programmer, or do I want to be a hacker and make a kickass app (that can eventually become a startup)?"
The former is great - especially if you're planning on working for big prestigious software company that's into that kind of thing. The latter, however, doesn't necessarily require knowing the theory, fundamentals, and ins and outs of a programming language. If you only want to build a single app, your time would be more wisely spent jumping into development and figuring things out as you go. This way, you'll learn everything you need to develop your idea without wasting precious time (and brain space) on things that may not apply to you.
My own experience is similar to what you are describing. I had a startup idea but had never programmed a day in my life. I figured out that Ruby on Rails would work for me so I started reading every single tutorial/ebook that I could get my hands on. I tried for months but nothing stuck - I just couldn't get the hang of it. Eventually, I said screw it and started building my app (with very little knowledge of what I was doing). Currently, I wouldn't say development is finished, but I do have a beautifully working MVP. When an obstacle crops up(and they do quite often), I google my very specific problem and 99% of the time the answer appears as a blog article or stackoverflow question. On the rare off chance that I can't find a solution to my answer, I post a question of stackoverflow with a detailed description of my problem (and usually some code). Every single question I've asked has been answered in minutes - an invaluable resource. A few weeks ago I started working on my second and third apps. I was amazed that I actually knew what I was doing, but it validated that I had actually been learning how to program the whole time I was hacking through my first app.
I think the question you should be asking yourself is this "Do I want to be a brilliant programmer, or do I want to be a hacker and make a kickass app (that can eventually become a startup)?"
The former is great - especially if you're planning on working for big prestigious software company that's into that kind of thing. The latter, however, doesn't necessarily require knowing the theory, fundamentals, and ins and outs of a programming language. If you only want to build a single app, your time would be more wisely spent jumping into development and figuring things out as you go. This way, you'll learn everything you need to develop your idea without wasting precious time (and brain space) on things that may not apply to you.
My own experience is similar to what you are describing. I had a startup idea but had never programmed a day in my life. I figured out that Ruby on Rails would work for me so I started reading every single tutorial/ebook that I could get my hands on. I tried for months but nothing stuck - I just couldn't get the hang of it. Eventually, I said screw it and started building my app (with very little knowledge of what I was doing). Currently, I wouldn't say development is finished, but I do have a beautifully working MVP. When an obstacle crops up(and they do quite often), I google my very specific problem and 99% of the time the answer appears as a blog article or stackoverflow question. On the rare off chance that I can't find a solution to my answer, I post a question of stackoverflow with a detailed description of my problem (and usually some code). Every single question I've asked has been answered in minutes - an invaluable resource. A few weeks ago I started working on my second and third apps. I was amazed that I actually knew what I was doing, but it validated that I had actually been learning how to program the whole time I was hacking through my first app.
Good luck!