Once you get past 40, you realize that you're somewhere near the half-way mark. You may have even passed it. Suddenly every second becomes precious. This feeling only intensifies as you continue to age.
So how do you know if you're wasting those precious seconds? That's a complicated question to answer, but I'll give you a simple step by step way to make sure you're not.
Step 1: Make 2 lists - one for things (activities, people, things, etc.) you like and one for things you dislike. Twenty of each should be all you need.
Step 2: Do at least one of the things you like every day. If there's something you like of particular importance (perhaps because it generates income or keeps you healthy) try to do it every day.
Bonus Step: Ensure you aren't doing more than one thing you dislike every day.
There - now you're no longer wasting your life. Ridiculously simple. But guaranteed to work.