A truly refreshing outlook on life, that hopefully will still be a long one far beyond your 30 and a bit years, not just for your sake but for those who are around you - I am sure your outlook also motivates and encourages them.
When I was 12 my mother was diagnosed with Breast Cancer, and was given 4 months to live. Her view was not unlike yours and cherished every moment no matter how trivial it may have seemed. As a twelve year old it was hard to comprehend, but ironically her philosophy was ingrained in me, and usually I try to see the good in everything. Never can I recall her complaining about anything.
The good news was my mother defied all the odds and lived into my 20s, saw me grow up, mature and get a career, of which I know she was proud. I was actually in London when I got the call of her passing, but deep down knew she would make the most of whatever actually comes next.
I wish you the best Lizzie, there are not enough people like you in the world.