It's the wrong question: instead ask 'what stops me acting like a manager'
Why? (1) Don't wait for permission: act like a manger now (2) dress like a great manager, turn up on time like a great manager, address what needs to be addressed like a great manager (3) volunteer for projects and anything which gains you people and resource experience (4) when a job comes up, talk about what you have been doing and ask for a trial period (5) knock their socks off with what you have achieved (6) it's a mindset not a permission.
Bonus 1: You, Only Better
Bonus 2: Wrong Question 1: Where do I find the (loads of) money I need to start my own business?
Bonus 3: Wrong Question 2: How do I escape from the rat race?
Bonus 4: Wrong Question 3: How Do I Find More Time?
Bonus 5: Wrong Question 4: How Do I find my passion?