If you want to go to Florida by car

But the human brain is ACTIVE. It anticipates, or looks for, certain constructions. Thus, having perceived a "to," the brain then seeks either an infinitive or an object of the preposition. (Scroll down for additional comment.)

If you want to go to Florida by car, you must plan to drive awhile.

This may explain why many readers find the misspelling of "to" to be so annoying. In a reader's mind, "to" evokes the question "to what?" "Too" evokes no such question. Thus, in a sentence such as "He wants to go too the store," a reader may process "too" as meaning "also," and then hit "store" and be momentarily stumped with how to chunk it.