Thank you so much for your letter. It was wonderful to hear from you and to get all your news. I was overjoyed when I found your letter in my mailbox. I was desperate when I heard about your grandfather passing away since I know how close you two were, but, at least, I am glad to hear that Amanda is in a blissful condition. Congratulations!
I was elated to hear about your plan to write a book about people’s memories. You are certainly welcome to use mine.
I must have been about five at the time, certainly not older than five and a half because we still lived in our old house by the sea. Down the coast there was a ghastly old house looking sinister as if it had just come out of a horror movie. I was considerably above average for my age, walking, talking and even thinking on my feet. Something about that house drew me in. One day I wandered away from my grandparents who were supposed to be looking after me, and went straight to the old, ghastly house. I remember vividly that the house looked completely different on the inside. It was cosy and tranquil. Unfortunately, to my disenchantment, my exploration was stopped abruptly as I was found and taken back home by my worried grandparents. Back then I realized that one should neither judge a book by its cover, nor a house by its exterior. I went back there a few years ago to see that the old house had survived the ravages of time and is still standing strong, looking as ghastly as ever.
Another memory is not so distant. It happened not so long ago. My sister and I were both on our winter holidays. So, as usual, we went to our cottage in the woods of Tara. I cannot begin to describe how serene I feel every time I put my feet down onto the cold gravel and breathe in that fresh mountain air. I think Tara is greatly underestimated in comparison to Zlatibor and Kopaonik. Everyone wants to go to Zlatibor and Kopaonik. They are beautiful mountains but they cannot compare to my Tara at all. Anyways, our cottage is just one kilometre away from the bear sanctuary that is located deep in the forest. One night as I was lying awake I heard a loud roaring noise. I went numb, since just a week earlier a bear had attacked a man leaving him seriously injured. I couldn’t do anything so with that unsettling feeling I fell asleep. When the morning came, I found out that a bear from the sanctuary came just fifty metres far from our house and destroyed all the beehives. Crazy, right?
I sincerely hope that these memories will be useful for your book.
 Think on your feet is an idiom which means that you think and react quickly, especially in a situation where things are happening very fast.