How often are you reapplying sunscreen?

I see most routines people post saying they apply sunscreen in the morning, but I also see sources saying you need to reapply sunscreen after 2 hours. That sounds like a nightmare! Seems like that'd be caking it on layer after layer 4-6 times throughout the day. How are you guys managing this? I got burnt after sweating heavily at the gym, not reapplying, then walking home. So I guess there is some need to reapply after sweating. But several times throughout the day seems like a tall order.