It's possible to reset it If you have set the Gmail account on your mobile device,
:-.insert the unlock pattern for 5 times i.e. any pattern of your choice which could be right or wrong it doesn't matter.the idea is to get to the "Forgot Password Popup menu"
:-.when the "Forgot Password" popup menu appears click/tap on it
:-enter your correct Gmail username and password
:-VOILA you can now enter the new unlock pattern
:-repeat the Unlock pattern to confirm.
If this fails then there is no other way to get it as an end user unless if you walk in to the warranty centre. alternatively you can do a hard reset and start afresh but NB:You will lose all the contents on your mobile device to factory defaults