Not sure if this was the OP's intent, but doesn't
"a place where people can learn by being given some random topics" basically describe sites like Hacker News?
Edit: Just noticed that the OP is the post's actual author, so I assume this was not in fact the implicit joke. Given that, the blog post would be more compelling if it indicated how such a place would be different than HN (or, say, Reddit)...
Thanks @pinko for your comment. You are right. It might sound similar to HN. But HN is sort of like tech-related. I am thinking of a place to learn truly random stuffs, or scientific stuffs. But you made a good point, it sounded quite like Reddit!
It seems to me that there is a fundamental difference. Reddit and HN are good for dropping the user into a giant bin of information, but this seems to be focusing on things we can actually categorise as knowledge and, hopefully, would include ways of actually encouraging and reinforcing that knowledge. The idea's very rough, but I can see a place for it that HN/reddit/what have you just doesn't fill.
Thanks @masterzora for your kind words! I definitely agree the idea's still very premature. And that's why I would love to get some inspirations from the experts in HN community.
The rationale is really to encourage and engage people to learn something new, different and useful.
Edit: Just noticed that the OP is the post's actual author, so I assume this was not in fact the implicit joke. Given that, the blog post would be more compelling if it indicated how such a place would be different than HN (or, say, Reddit)...