Widget sidebar slow loading time.

I have noticed that a dynamic sidebar is adding about two seconds in loading time on the page where is added, it dose not matter if there is a widget or 100 widgets in it, it just makes the theme loading time very bad.

Why is this happening and is there something that I can do about this?

Thank you.

I fixed it by loading it with AJAX but still why is this happening makes no sense.

Any suggestions are appreciated it.

Thank you.