My god, what a horrid thought! It might mean anything from "I have Altzheimer's" to "I once acted in a film with a chimpanzee". Without more context it's impossible to tell, but the emoticon looks more like Tintin. I think it's a joke.
Thank you very much for your kind reply. the context is as follow:
All over the country these days, electronic mail messages are concluding with this odd little punctuation sequence

or one of its many variants, like :-( .
These are “smileys,” so-called because when you tilt your head to the left they look like little faces with a colon for eyes and a hyphen for a nose. Thus when a message ends

, it means “just kidding.” If it ends :-(, it means “I’m depressed.”
If it ends 7 :^), it means “I resemble Ronald Reagan.”
In fact, I have looked up the icon on the net and found its definition "show Reagan's hairstyle with accentuated part". What I didn't understand is why people use an icon to show Reagan's hairstyle and in what situation they use this icon.
Thanks to your explanation, now I know it's only a way to show our feeling on funny things.