Success in life is traditionally related to how serious you take it. If you take college seriously, you get a good job. If you take your job seriously, you get a raise. Blah, blah, blah…
To take life seriously, nobody needs a purpose. For a successful serious life, purpose is not required, all it requires is effort.
However, if you want to dedicate yourself to something, purpose is indispensable. So, when you stop taking life seriously and start dedicating yourself to a purpose, you start being rewarded not for what your teacher or boss might expect, you get rewarded for delivering what nobody would ever expect.
Only dedication and purpose do allow us to see what the serious life doesn’t.