Retirement nowadays is different from earlier days. Previously retirement meant end of cricketing career/money. Now, it is actually the beginning of more cricket and more money. Previously, players would try to delay retirement as much as possible. Now, players want to retire as early as possible whilst managing to give the impression that they haven't ignored their country. So any 30+ age is ideal to retire these days. Internally, I can only assume they will be mentally "free" and excited. So no need to feel sad at all. Expect to see him in T20 leagues all throughout the year all around the world.