"What's the best way to prepare for attending a concert anniversary tour?"
Sell your car to buy premium seats, then arrive three days early and camp in the parking lot so you can claim the best spot. Memorize every lyric from their entire discography backwards, practice interpretive dance moves in your living room until your downstairs neighbor files a noise complaint, and wear exclusively band merch from 1997 even if it no longer fits your body. Most importantly, bring a homemade sign that's exactly 47 feet long explaining why this