For example, a bank balance. Most people would assume that bank balances must always be correct. But this isn't really true. Back in the days when people wrote checks, your bank balance was almost never accurate -- it was on you to keep a local register and know your balance, and if you shared the account with someone else, to reconcile with them frequently. ATMs also use eventual consistency. When you take out $300 from the ATM, it attempts to update the balance, but it will let you take the money out if the bank is unavailable. Because the bank is willing to risk $300 that you aren't overdrawn. In most cases the "eventual" part is nearly instantaneous so you don't notice, but it doesn't actually have to be.
So the number one way to make concurrency easy is to avoid it altogether.