To give you an idea on what sense of purpose is have a read of this brief document:
https://www.beyondblue.org.au/docs/...bility/sense-of-purpose-hand-out.pdf?sfvrsn=2
Only you can work out what it is for you.
However the lack of a sense of purpose is I believe a key reason why some males curl up their toes within two years of retiring, and in particular those that did not wish to retire but were forced to.
Well that may work for you, but I personally will need a lot more than just than managing my money and meeting basic needs. That for me would be more being in limbo than being in retirement.
As to being happy...that to me goes to quality of life and to me a retirement if all I did was existing would be bland and unpalatable for myself. I could not be happy with no sense of purpose. But being happy is more than just having a sense of fulfilment. Again what makes one happy is unique to the individual.
For me personally a retirement of doing nothing (if that is truly what you only do <or rather not do!>, but as you at least travel it seems that you do more than nothing) would drive me stir crazy. Don't get me wrong, some days of just chilling will be on the agenda. But I need more please.