那是最美好的时代，The characters for "best" are 美好.
Now, one of the things I've found is that different dictionaries will translate the same Chinese word*** in different ways. So that if you look up 美好 in this dictionary it is translated as "happy, fine, ok"; but this dictionary gives "beautiful, fine" -- not quite the same. And then this dictionary gives "wonderful". All three, that is, give quite different meanings to the same word. (And none of them, incidentally, make it sound like a good translation for the English word "best". Now, I'm not saying the translators were wrong -- it's quite possible that in the context 美好 is a perfectly good translation for "best" -- but either they were wrong, or the dictionaries aren't giving very complete answers, or the context dependence is doing a lot of work here.)
But as it happened, I didn't actually look up 美好 directly. It happened that I knew the pinyin for those two characters (isn't true for a lot of characters, but it was of those), so it seemed easier just to type "meihao" into a dictionary (as it happened, this one) instead. As pinyin goes, that's incomplete, since I didn't mark the tones, either through accents or through the (far less aesthetic but easier to type) numbers. But it seemed like it would work.
And it did. It gave two options for meihao, spoken with different tones. It could either mean 美好, wonderful, or 煤耗, coal consumption.
Now, note the difference between the pronunciation of these two words is just the tone of the second syllable. (Ordinarily 美 is pronounced third tone, but before another third tone it switches to second, and comes to match 煤.) In other words, a tone slip in a single syllable could have you say, accidentally, "It was the coal consumption of times".
This is why I'm not studying Mandarin. I'm just fooling around with Mandarin. Because it's too damn hard to actually learn for real.
* A reminder of what this means, from the earlier post: "The difference between fooling around with Chinese and studying Chinese is that I'm not expecting it to go anywhere, that I'm not claiming (even, or perhaps especially, to myself) to have learned anything, that I'm not being systematic about it, and that it's just for the pleasure of discovery rather than for anything that may result from it (since probably nothing will). It's less about Growth, Self-Improvement and Opportunity than it is about idle procrastination and lazy curiosity."
** "It was the best of times, it was the worst of times, it was the age of wisdom, it was the age of foolishness, it was the epoch of belief, it was the epoch of incredulity, it was the season of Light, it was the season of Darkness, it was the spring of hope, it was the winter of despair, we had everything before us, we had nothing before us, we were all going direct to Heaven, we were all going direct the other way -- in short, the period was so far like the present period, that some of its noisiest authorities insisted on its being received, for good or for evil, in the superlative degree of comparison only." -- The comic gives about two-thirds of the sentence -- up to "other way".
*** Yes, I said word: most modern Chinese words are made up of more than one character.