There's an interesting old saying, stating (This isn't the exact saying) that
when you interact with people and meet new ones, they take parts of you with them,
and you lose bits of your essence to everyone you regularly speak to and do things with.

This is true.

What if it should happen that you've given much to your friends and the
people you've met only to find out at a point that you feel you haven't,
in the end, received enough in return, and now you feel like you've
exhausted your giving and can't give anymore?

To get to know people, to get closer to people, you have to be willing
to "give and take". But what happens to you once you reach a certain
"point of saturation" when you don't any longer feel any joy in
again going over things you've already processed with other people?

When you cannot any longer bring out new things,
and you don't want to say again the things you're already said,
even if you've said them to someone else.
Tired of repeating.. or perhaps also tired of starting over.

I guess your game is over. You cannot give anymore, you are no longer capable
of creating bonds with new people, because you don't appear to have anything
worthwhile to offer to them. You've run dry, beached and immobile.

No person is an unlimited treasure trove of such energy, and I think
that everyone is bound to reach that tiring point. I guess it's what you
managed to accomplish before you hit the mark that counts, but what if one
should run out early on in life, yet craving for more?
What should one do then? Compensate lack with effort? End oneself?
Be happy with what it is that one has to be happy with?

Well.. life doesn't provide anyone with neat solutions,
and problems can bring about a true dead end anytime, so there just
might not be a solution that'd allow for the player to continue.
Maybe once you hit a wall, all you can do is wait until you run out of time.

One shouldn't give too much to anyone particular?
Just keep your secrets?