While working, our brains are being continually exercised; after we stop working we need to replace that mental activity. This may mean taking up a new hobby or leisure pursuit, learning a new sport, volunteer or community activity or simply engaging in some regular mental activity such as crosswords. No-one goes to the gym once and considers themselves physically fit - it is always a work in progress. The same applies to mental activity - it is ongoing. Kids bunk beds retirement can either be the end of a useful working life, or the excitement of beginning of the rest of your life - where you are free to do whatever you want. Treating retirement as an exciting new adventure is the best way to guarantee fulfilling retirement.