That backpack is currently at college with my son, who used it all through high school as well. It is by far the oldest and most durable daily-use object I’ve ever owned.
In 2004 I was very young and all my income came from summer jobs, so I got a backpack from Walmart. It was one of their nicer models, had a lot of features and looked pretty good. IIRC it cost $20. I had worked all summer to save for an MP3 player, and 2 months after getting that backpack I getting off a bus, when I realized there was already a hole in the bottom of the bag. My MP3 player (a creative zen micro) had slipped out of the bag, and someone had already picked up my MP3 player and walked away with it. Adjusted for inflation I spent over $500 on that MP3 player. Even as an avid backpacker, I have not spent that much on fairly nice packs.
In 2007 I splurged and paid $100 for a backpack from Deuter, and I also felt a lot of guilt as that was a huge amount of money for me at the time for something like a backpack. It's been nearly 20 years, it's not just that the backpack is still working, it still functions virtually like new. None of the seams are stretching, even though it's been through incredible overstuffing and abuse. All of the zippers are smooth as silk, and even the cushioning on the straps and airflow offsets on the back are still supple and supportive.
I think Targus stopped making this model (maybe a trend towards smaller laptops), hopefully this one will keep working for a while before I need to find a good replacement.
I'm 48 and not only do I still have it, it still looks like new, with no real care taken of it - wear it, put it away. The only issue I had was the liner in one arm pit started to unstitch a couple of inches, and a tailor took care of it in 20 minutes for $10 a decade ago.
Good lightweight backpacks are not that durable. I have 12 years old 1.5 pound osprey, still in use, but age really shows.