Question: I spend about $20-30 a week on my debit card, with periodic $200-300 purchases every few months. I've thought about getting a credit card the moment I turn 18 and using it to buy everything, then immediately paying it off. Assuming I only use it to buy things I can afford (which I trust myself to do), essentially treating it as a debit card, is this a good idea? Or should I wait until I'm a bit older? 

Assume that I will only spend money I have in my bank account at the time I spend it and that I will keep track of how much I spent and never spend more than I have.

Joe Taxpayer recommended I post an update: I ended up getting a card, and from my perspective the only thing that's changed is that it takes things ~24 hours to show up on my statement and I don't have to enter a PIN when I checkout. Should I add this to the question? I know on other SE sites people generally don't like updates in the questions

Answer: 
> 
> Assuming I only use it to buy things I can afford (which I trust
>  myself to do), essentially treating it as a debit card, is this a good
>  idea?
> 
> 
> 

This is definitely a good idea.

From my own experience, before I got my first credit card through my local bank (age 18), I tired to apply for a card that has cash back rewards and was rejected because I didn't have any credit history. After I had the card from my bank for 6 months, I applied for [this Capital One](http://www.capitalone.com/credit-cards/quicksilver/) card that I've had ever since.
Definitely not. Credit cards only exist to suck you into the soulless corporate system. What you want to remember here is that you can't trust banks, so you'll want to convert all your savings into some durable asset, say, bitcoins for example, and then hoard them like Smaug until after the Fall.