If you go to the
User Control Panel/"User CP" (<---linky, but it's top left, on the darker blue menu bar) you'll see the first item on the left under
"Your Control Panel" is
"Your Profile". If you click on this, you'll see the same type of profile you get when you
"View profile" of other members by clicking on their username in a thread and picking that menu item (except, obviously, for yourself). Under this, there are tabs for
Visitor Messages,
About Me,
Statistics...and a couple of others, but it's the
"Statistics" tab you want. Click on that tab, and you'll see multiple sections, the first of which is
"Total Posts". There you can see links to
"Find all posts..." or
"Find all threads..." started by yourself.
Cheers,
Marc