Are dead people really dead, or simply still alive in another form? To be dead requires a state of non existence, yet that would only be possible in a void. Yet perhaps it could be argued there is no such thing as a void, otherwise existence would not be.
So yes, I do believe 'dead', to use your term, people can be aware of the living. Perhaps the question should really be whether we are still relevant to them in their fresh existence / incarnation.
You have to live 'your' life for yourself. Love yourself first and the rest comes. Also why would the opinion of someone dead matter more than someone who was still alive (speaking conventionally). The key word here is 'thought / think'. Surely their status of existence is neither here nor there?