Life will turn you into a bitter, resentful person if you don't watch yourself 
Worrying about bills and all the other bullshyt that comes with it, while your life slips away. One day you wake up and you're 50 wondering where all those years went.
There's also the element of fear. If you don't learn how to manage it, having children will make it even worse. Your father probably worries a lot and is anxious about a lot of things - especially concerning his kids.
In his mind, by dumping all that negativity on you he is "preparing you for life". He doesn't see it as something that could cripple you from pursuing a meaningful life. It comes from a good place, but it's very destructive if you adopt it as your outlook.

Worrying about bills and all the other bullshyt that comes with it, while your life slips away. One day you wake up and you're 50 wondering where all those years went.
There's also the element of fear. If you don't learn how to manage it, having children will make it even worse. Your father probably worries a lot and is anxious about a lot of things - especially concerning his kids.
In his mind, by dumping all that negativity on you he is "preparing you for life". He doesn't see it as something that could cripple you from pursuing a meaningful life. It comes from a good place, but it's very destructive if you adopt it as your outlook.