Too big to fail, too drunk to care, too good to be true. When something is in excess, English commonly uses the adverb "too" to express such states of affairs. Japanese can do similar things with the verb sugiru (過ぎる, to pass by, exceed), which has basically the same meaning as "too," but a far larger range of application.
Resemblance with "too" is still close when sugiru is attached to adjectives. It works with both i- and na-adjectives, as in muzukashi-sugiru (難しすぎる, too difficult) and kantan-sugiru (簡単すぎる, too simple). It also attaches to negated forms, which gives us muzukashikunasa-sugiru (難しくなさすぎる, "too un-difficult," or "much easier than should be") and kantan janasa-sugiru (簡単じゃなさすぎる, "too non-simple" — that is, "far more difficult than expected"). In casual Japanese, sugiru is frequently shortened to the nominal form sugi, as in hayasugi (早すぎ, too early) or ososugi (遅すぎ, too late).
Unlike the English "too," sugiru also attaches to verbs. Some acts that are commonly done in excess are tabe-sugiru (食べすぎる, eat too much), nomi-sugiru (飲みすぎる, drink too much) and ii-sugiru (言いすぎる, say too much). Note that when an adverb is added, sugiru still attaches to the verb, not the adverb. Thus "run too fast" is not haya-sugite hashiru or something, but hayaku hashiri-sugiru (速く走りすぎる). Negated verbs are also possible, as in doryoku shinasa-sugi (努力しなさすぎ, give too little effort) or ki ni shinasa-sugi (気にしなさすぎ, take too little to heart).