once you have partaken in 'sessioning' to such a point that you have reached satisfaction with both your aesthetic and technical performance and possibly until such a time as to have received 'props' from your fellow bicyclists, you can categorise that particular trail or trail feature as having been 'owned'. In the case of a trail feature which necessitates your wheels leaving the ground e.g. a jump or a drop, which is of sufficient difficulty or 'gnar', common acceptance of ownership comes after the 'sessioning' of said trail feature three times over. hence the expression 'three times and owned'.