How is this hard? It's actually quite handy. The only problem is that you can spend considerable amounts of money without noticing because, you know, no one keeps track of their coins...
Actually, Italy has requested many times the substitution of 1€ and 2€ coins with banknotes because of this but the ECB never agreed.
And in the Netherlands and Finland coins of 0,01€ and 0,02€ are not minted, prices are rounded to 5 cents. Such coins, minted by other countries, are a legal tender, though.