What you have is now. Only, now.
And as time progresses towards the future, you have yourself instantaneous new nows. With the old nows out of reach and now useless to you, except of course, if you have made something of the old nows which you can take along to the new now.
With every new now comes new challenges and responsibilities – well for most people.
And as nows pile, so does the responsibilities and challenges one has to deal with it.
If you know, there isn’t a nirvana, where all is ok and taken care of, then perhaps, you will start the work to arrest the occasions, the nows, and make them count.
Where will fails, perhaps skill can help.
You do not have forever. You create forever.