I was 28 when I started. Always wanted to in my early 20's but I wasn't sure I could commit to learning another instrument and everyone said that it was hard, and a friend of mine also gave up aftering learning a few years. Maybe that was cos his dad made him.
But anyway have been learning for exactly 2 years now, am in Grade 3, am not regretting and looking forward to finishing up to Grade 8 eventually.