benign, bereaved, auspicious, affable... are the last words I've learnt today.
Those are charming words to learn, and you should take pleasure in using them... but only occasionally. Savour them like a fine, rare whisky, brought out for just the right occasion. English has thousands of words of that calibre; words you only use once, but when you do get to use them its eminently satisfying.
If you're devoting yourself to vocabulary, a very useful website is this: testyourvocab.com. It's a great little measure of your language level which, while very basic, seems to mirror the results of the much deeper tests offered by companies like English First. Take the test, then read the Blog section to understand how your score translates for foreign learners of English.
Based on your result, you can then sign up for vocabulary.com; an excellent tool which teaches you targeted vocabulary based on what you already know. The more you use it, the better it learns your level, and modifies its word list accordingly. You even get real life examples taken from contemporary sources of news, speech quotes, magazines and even literature, so you can get the word in context. Five minutes each day (20 questions) will yield significant improvements.
Then you can sit back, look at the luscious rufescent shades of Poland's trees as they fade gloriously into autumn, and quote to yourself the first line of Keats' Ode: "Seasons of mists and mellow fruitfulness", enjoying and savouring the mellifluous assonance of that line and ignoring the vitriolic bile of internet forum comments :-D