Has anyone watched Christopher Nolan's Inception?

Hi everyone, rishab here!

I love watching movies and I'm sure most of you guys do too😁.

I recently watched Inception and boy was I confused!😂
Is something like this possible in real life!?

Why was Cobb still young and Saito so old!?

This is a shout out to anyone who can explain to me the ending!!
And the biggest question of ALL!
Is Cobb still in a dream!?

Thanks in advance guys..hopefully some of my doubts will be cleared.