Locked out

Update:  I restarted the phone, and it let me back in.  Why do I never think to do that?

When I thought I had lost my phone, I put in a PIN lock for safety if I lost it again.  Well, as of this evening, the phone is refusing to accept my PIN and I can't get into it, to make calls, get Emails or take photographs.  And I don't know what to do about it.  When I set the pin, the message was, don't forget your pin, because you can't change it.  My mood is as black as this mono shot taken with my little camera of some flowers I saw today at Central Market when I went for my walk, but the sciatica is so bad that I had to cut the walk short.  What else can go wrong today?