But if you kept that car for fifty years, it'll become an...

But if you kept that car for fifty years, it'll become an antique and you'd sell it for a profit.
I know little about this game, though I'm learning fast, but shares are not like cars. The price of a car goes down immediately after you're given the key to it. The price of a share, on the other hand, might go up and down like the proverbial yo-yo and until something drastic happens and it's wiped off the market, then you neither make nor lose any of your precious money until you sell them.
I think that's the basic rule of share trading.
But I do stand to be corrected.