present perfect or used to

"I always wondered about" sounds more correct to me as "have" implies you're still wondering.

second one seems incorrect to me; "I used to wonder about aquatic...." would be more appropriate.

I chose to study this program because I have always wondered about the life/lives of aquatic animals' life
......because I used to wonder the life/lives of aquatic animals.

The first is more natural, in my opinion. The second suggests that you no longer wonder about the subject, as karansardana suggested.

Always use a capital

Thank you. I want to ask one more question to understand exactly.
what is your favourite colour and why?blue, because when I was a child, I always thought there was another world under the sea.
<or I used to thougt there was another word under the sea.>

AnonymouswWhat is your favourite colour and why? bBlue, because, when I was a child, I always thought there was another world under the sea.

That's fine, with my corrections. So is this:

Anonymous I used to thougt think there was another word under the sea

Sorry. Of course I meant 'think' but I want to know which sentences I should use.. used to or past tense or both of them are right..

Thanks in advance.