Drupal 7 vs Drupal 8, In learning prospective.

Hello All,

I need guidance by you people!

I am a Drupal Developer, I worked on Drupal 6 & 7.
I am having moderate knowledge of Drupal 7,

like creating custom module, with some well known hooks, like hook_menu, hook_form_alter etc.

I am not much good In drupal 7 all hooks and not aware why mostly api used for. But I am continuously learning .
and I can do by learning.

So my Question is:
1. Should I learn Drupal 7 completely?
2. Should I start Drupal 8 now? and learn D7 whatever needed in development.
because the near future for Drupal 8 I think, (and after 1-2 years, people forget drupal 7, like drupal 6)

So future is in D8, So am I not wasting time on D7?
Please suggest!

Drupal version: 

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