That the whole idea of a pool.  It's like buying lottery tickets in a group, 1000 person each buying a ticket for example.  Sometime, someone have the winning number, but the gain is shared across the whole group.  The 'block found' is just an indication, an add-on feature of the pool to say that you had the lucky ticket, 'just for your record'.  Still, you get reward according to your contribution.  The more numbers you put on your ticket (the higher your hash rate), the more you earn.  You may be 'unlucky' and never find a block, but still, you put your chances in, and get rewarded accordingly.  Or you may be extremely lucky, like me who happen to have found 2 blocks which go against the odd, still I only brought the equivalent of 17BTC to the pool to date (and brought like 8~10BTC total at the time I solved the 2nd block).  But I don't get more reward, noticed or even get praised for it, that's just pure statistical luck.

And no, if you do find a block, you can't solo submit it, as you have just the header, and can't re-create the whole block, which only the pool know how it assembled it.  The only thing you can do if you want to 'disturb the odds' is negatively by holding (not submitting) a winning block if you happen to find one, but it bring no goods to anyone, as the pool will then be short of 25 BTC.