Actually, that's not true. But you must feel like Rip Van Winkle. I hiked and backpacked 20 years ago, too, but kept at it. And NOTHING I own today bears much of any resemblance to stuff I used 20 years ago. So you must be thoroughly dazed by it all.
Luckily, you've narrowed your question to warm-weather hiking. And the answer is: Synthetic. Synthetic everything-almost (explanation to come shortly). I wear underwear made of Coolmax or polypropylene, both of which dry fast and don't chafe. Shorts, nylon, or a nylon and Cordura blend (example: Mountain Hardwear's Synergy short, $78, which also incorporates Schoeller's superb Dryskin material). Shirt: Coolmax again, or something similar such as Patagonia's silkweight Capilene (T-shirt, $32). Much, MUCH better than cotton, which was of course the standard in 1982 (wow...that was a long time ago). And a good hat, something like Outdoor Research's Kalahari Cap ($24), to keep the sun from baking your brain.
The exception: Socks. Assuming you're wearing a midweight boot or heavier, then the 1982-era rule about liner socks and oversocks still applies. I like liner socks of, again, Coolmax or polypro. But for oversocks, Merino wool is the ticket as its fibers absorb buckets of perspiration so your feet and boots stay dry. Smartwool's Hiking Socks ($16 a pair) are the thing to have.
So there you go. Say, have you heard about this thing called the Internet? You can make a lot of money buying stock in places like Pets.com! You should try it!