That's a hidden way of arguing there can be no meaning to life without a creator, a feeling that religions the world over have handily exploited.
Meaning can derive from yourself, you can feel good about your own acts within your own reference frame of morality that you have derived from your experience with the world.
There's nothing wrong with that and it is just as satisfying, or even more so than some externally supplied meaning.
Meaning can derive from yourself, you can feel good about your own acts
I can feel good about shooting heroin, but that doesn't mean it's right (or that it's not!). It really ends up sounding like "Do what makes you feel good, and try not to think too much about why it makes you feel good". That's not necessarily bad, but I haven't seen any argument that it is good, other than that it's not necessarily bad.
If what you're looking for is what's most satisfying, I'll agree that introspection and experiment will tell you that. If you're looking for what you ought to do, what's really "meaningful", it's not at all clear to me what can tell you that. Or that anything can, or that it's even a question with an answer. At least if there's no answer, continuing to think about the question can't be wrong. ;)
World of warcraft characters are not self aware, but if they were, my point is exactly that they could aspire to higher meaning than fun for players, by their own standards of morality and what they choose to be fulfilling.
You can feel good about shooting heroin, for a little while, and then you'll realise that it is not all it is cracked (pun intended) up to be. So you will most likely either revise your value system or you'll die of an overdose.
Just doing what makes you feel good is not a very good system of morality, since it obviously allows you to do good to yourself at the expense of others. People that have such tendencies are usually labelled either unable to empathise or psychopaths depending on how far they go in their pursuits.
What you 'ought' to do, is to try to define a set of rules for yourself that start from axiomatic things that any healthy and well thinking person can perceive as 'good'.
It's not a coincidence that most laws tend to start off from basic principles like 'property is ok' and 'killing is not' and work out a whole series of codified laws from there.
For a moral viewpoint on life and a feeling of satisfaction you could very well do the same, on your own almost without external input.
Some people will come up with extremely selfish sets of rules, which is fine as long as they fit within the legal framework and make them feel good, some will do much better than that.
And some will fail, and end up in jail or become ostracised from society.
Whenever you see yourself saying, "you ought to"/"it's good to"/"it's moral to", notice the immediate reason that the statement seems true (assuming it does) is to satisfy some goal. You have a goal of not hurting other people (or, to say it another way, you want not to hurt other people), but while that suffices for directing your thoughts and actions on this level, if you back up a level, you'll see that this goal is in service of another goal. If human goal systems were regular and consistent, there would ultimately be a topmost goal which all this was pointing at. But that doesn't seem to be the case, so we're left shifting about aimlessly, considering only that which we happen to consider (our happiness, the happiness of others, life satisfaction, or whatever) without anything to direct what we ought to be doing.
Making up your own meaning doesn't solve this problem, but only ignores it. It might be that it's unsolvable (I currently think so, at least), but in that case, it can hardly matter that one keeps looking.
If your philosophy is consistent, then the above statement is only true for you, correct?
Then why aren't we allowed to integrate religion into our rules to live by? Are some things "external to the self" allowed, and others disallowed?