I disagree. I am a developer (so far from an extremely basic user) and my nearly-six-year-old Macbook Pro still serves me well.
If your computer is still in pristine condition without any repairs or replacements, then consider yourself lucky. I'm curious how you've kept your internal clock battery and regular battery alive and productive during this entire time. Out of the 10+ computers I have owned, I have never had a computer last that long without something breaking down, and this includes desktops and laptops, from Apple, IBM, Dell, etc.
I still stand by what I said, and by my standards, I'm confident that the user experience for you using even something basic like the internet (unless you visit sites without any media whatsoever) is far from what it was when you first purchased your Mac.