Hate to tell you, but you'll probably be taking synthroid for the rest of your life. And the dosages may change too. Your doctors will check your levels every so often to make sure you don't need a higher or lower dose.
I didn't read your other post; was it about 6 weeks before another blood test was done (after starting the med)? That's how long docs usually wait when you first start taking it or have your dosage changed. It sometimes takes a little while before the levels are where they should be. My DH is hypothyroid too and his took a few months before they got him leveled. They had to keep adjusting his dosage.
Like the previous poster said, your levels are good
because of the synthroid. Synthroid doesn't fix the thyroid gland; it just assists it (or in extreme cases, replaces it), to make sure enough hormone is in your body. If you stop taking it, in a few weeks your levels would be back to what they were, or possibly even worse.
There are other who can get into the more scientific explanations for you.

Hope this helped a little.
Glad to hear your levels are better too.
