|I know the OP hasn't really given a clear question, but the word 'internet' in there makes me think they mean the password to possibly access a router, or the ISP logon password, or the wireless password. None of them would be used regularly so I can see how they would be forgotten.|
So for a router password, the best option is to reset it - there will be a small pin-button that you need to press which will put it back to default settings - you may need to find the manual. or let us know the make/model for exact instructions.
If it is you wireless password then you need to either access the router's set-up page where it may be shown in normal text, if not then resetting, as above, is the best option.
If it is your ISP logon password then you need to contact them to either tell you what it is, or reset it at their end.
"I've always been mad, I know I've been mad, like the most of us..." Pink Floyd