look back vs. think back
Is there any difference between them (if used in the meaning of 'to think about something in the past')?

Can 'looked back' be replaced with 'thought back' in the sentence below?

I took that job offer and have never looked back.

Question

look back vs. think back
Is there any difference between them (if used in the meaning of 'to think about something in the past')?

Can 'looked back' be replaced with 'thought back' in the sentence below?

I took that job offer and have never looked back.

Answer

Your example "I took that job offer and never looked back" implies that you have no regrets.  You have only moved forward from that point.  "I took that job offer and never thought back" does not work well in this case.

Answer

No they are not interchangeable in the example you have given.

When I look back on my childhood...
When I think back to my childhood...

They are conveying the same idea in these examples.

Answer

not really.  It would not make sense to say "I took that job offer and have never thought back."  
You can say " I took that job offer and never thought about it again."