Test it yourselfby grinding some fresh pepper and comparing it to the pepper in your spice cabinet that's been there for years hidden behind the ground mustard. But start with the old pepper first or the freshly ground pepper will overpower it.
If you don't have a pepper mill at home, you may want to think about getting one. It's amazing how a simple ingredient like freshly ground pepper can dramatically change the flavor of a dish. I have an antique salt and pepper collection with over 100 pair of shakers and I only bring them to the table on holidays and special occasions for show. In my kitchen and at the table, I only use one of my pepper mills.
When I find a particularly interesting pepper mill in the store or on the Internet, I have to make a concerted effort not to buy it. I already have 6 or 7 different models of various styles in my kitchen cabinet but I find myself drawn to only using one. Which brand do I use? A simple traditional looking wooden one with a crank handle on top but because there are so many variables involved in choosing a pepper mill, you should pick one based on your own likes and needs.