Why should you care about interest rates?

When buying a home for the first time, one starts (for the first time) to hear the term "high or low interest rate".  But high or low compared to what? 
Is 3% considered a good rate? How about 4? and 5?
And then this other question comes up: Is it a big deal if I am buying a house now that rates are 4.5 vs 3.5 a year ago when my friend bought his?

The slide below shows you where today's rates are compared to where they were in the previous decades. Yes, as you can see they are super loooooow. It also shows you how much a month one would pay on a $200,000 mortgage. 

Conclusion: In this day and age, you might complain about an array of things from economy to politics to global warming. But as you can see you have at least one thing going for you:Low Interest Rates. Take advantage of them before it's too late.