Yes, and NOW is amazing!
Tomorrow! Tomorrow! I love you, tomorrow! You're always a day away!
In my experience, "tomorrow" arrives very quickly. It was only as a child that it seemed far away, but that was an illusion. It always arrived in no more than a day. So, it isn't "too far away" at all. You are going to have to live tomorrow with the consequences of today. Consequences can follow you all the rest of your "todays". There is no escape from causality.
That said, I don't see any reason why I shouldn't be happy at this moment. What is wrong with being happy?
But the method you prescribe, "indulging" oneself, which I take to mean a fetish for physical pleasure, is foolish in the long run. It is like arguing that one should gorge oneself on cake without any care for having a tummy ache in the next few hours, or the pounds one may add for the rest of one's lifetime, or the heart attack that will end one's life sooner than necessary.
Also, why focus on physical or unintellectual pleasures? Even Epicurus, who was technically a philosophical hedonist, advocated intellectual pleasures over physical pleasures. Reading an interesting book is preferable to eating that sugar-filled cake, and physical pleasures are only good to the extent that they relieve pain (such as of hunger) and bring one to mental tranquility.
But I am not a philosophical hedonist at all. While I'm not anti-physical pleasure and can agree with Epicurus on some of his advice, I prefer to focus my effort on self-actualization. Developing one's talents and putting them to good use is one of the most satisfying things in life, and one of the noblest. It is a far cry from simple-minded "indulgence".
Of course it really existed. It just doesn't exist now. That's no loss. For the rest of eternity, you still will have lived your life. Nothing can change that.
"Eternity" is no concern of mine. We are finite beings, and that is enough.
eudaimonia,
Mark