Agree re not explaining how it advanced his career. I did something similar about 10y ago. Was burned out so skied all spring, hiked and went abroad during summer, did a small amount of contract dev then gradually decided it was time to get back to real work. Don't necessarily think it helped my career nor was I expecting it to. Had to explain to recruiters and companies the gap in my resume which not everyone could relate to ... but ... so what. I had a lot of fun.