Just because you forget the light from time to time doesn't mean it goes away. It is permanent. It waits for you to return to it. And even after your next round of madness it is still there waiting for your return. It's never possible to remove it and it doesn't go away.
The ego's voice will come up with countless ways to persuade you that there is no light left anymore. All doom and gloom and darkness and death. It'll tell you there is no light and you might as well give up. This is not actually true. The light is always there, inviting you to join it.
To join the light you have to step out of the darkness, which means no longer dwelling in the ego's viewpoint and shifting your perspective to the Holy Spirit. Holy Spirit is the light of truth.
Taking things lightly or lightening up doesn't have to mean you've got to fake being happy or not care about anything. It means you get to genuinely be happy and carefree because the light sets you free. The "light side" is a way of looking, a way of perceiving, and a way of experiencing. It arises from sanity and truth and certainty.
The Holy Spirit's offering is one of peace and calm and illumination and clarity. He is available to show you a view of the world which can't be taken seriously, which shows you how trivial everything is here, and recognizes that all this ego stuff really is literally nothing.
What were you so worried about? It was nothing. What was so alarming and shocking? It's nothing. The Holy Spirit looks upon the illusion of "the dark side" and recognizes it is false. It has no truth to it. It has no credibility. It isn't to be listened to and has no argument that can convince the Holy Spirit it has a solid foundation. The Holy Spirit merely looks upon it, recognizes it is completely false, and that therefore there really IS no ego. It IS nothing.
If you are caught up in the story of life or the suffering agenda of the ego or the seeming bleakness of the ego's lies, then you need some light. You can't just `lighten up` by denying, however. Sometimes you have to work through your clouds and process your feelings and coming to a point where you're ready to look at things in a different way.
But at some point you DO need to open up to the Holy Spirit. You can't get to the light by ignoring him or not including Him. Similarly Jesus is with you in the light and you can't be in the light without Him being with you.
There is hope, because darkness is never permanent or true and the light is forever and always truthful. There is hope because the Holy Spirit is with you now and always will be and WILL NOT FAIL to lead you home to the light. We but need to be willing to stop listening to our own ego voice and turn within to listen to His voice of sanity and calm and reassurance.
Everything IS alright. Nothing has gone wrong. We are already saved.
Let's also remember that God Himself has appointed the Holy Spirit as his ANSWER to all of our suffering and darkness. God has GIVEN His support. He is in us, eager to help us in any way possible if we would allow it. His Help has no limits other than our resistance to accept it. It isn't bits of truth or quotes or thoughts or certain feelings or justifications or explanations that will save you, it is the LIGHT OF GOD - as the Holy Spirit - in your mind. This is what you need to connect with. He is your APPOINTED TEACHER, comforter, and friend. He is there for a reason. Use him.