There's many reason why you should not buy bitcoins. First and valid reason are do not accept buy if you're newbie and just step in. Better to learn and increase your experience learn what is block chain & how it work. You can't risk your money in bitcoin if you have zero experience.
We'll lose our money if we don't know how bitcoin works. Therefore better don't rush to buy bitcoins or cryptocurrencies. Acting without knowing what to do next is a stupid act. We can fail, and we might be experiencing the trauma of bitcoin failure. Next we'll avoid bitcoin. That's very bad.
Bitcoin is the most risky business for investor and maybe in the top of the list. Always look the price and and use your mind while investing.
If a newbie sees the historical reality, he may be surprised. The change in price is very unreasonable. Of course, they will learn a lot.