Sure do, you're not sure if you should take the Porsche or the Ferrari out today.
I do find it amusing that my car is worth about 30% of the camera gear I carry around
Like the cameras I keep the car until it falls to bits - a car is only for travelling from A to B, so as long as it does that reliably I keep it - usually between 7 and 10 years. This approach was why I didn't get a DSLR until 2009 because my film cameras were still giving excellent results. My 24-105 was on my film cameras first - the only lens I kept from those days.
I would expect in 5 years time my kit wont have changed much - perhaps added to at the short end. The 14mm, TSE-17 and new 24-70 are the only extras I can think of (apart from the 300). I am looking for a lot of flash at the moment - the McNally/Hobby/Arena exploits with gang flash look very interesting and I can see some use for it.
Kepp posting your great landscapes - I just cant 'see' landscapes whereas you seem to have the eye for them. They are very beautifull!