Can we really go back in time??

Is it possible to now - 30 years later - to do times that you were doing in HS or maybe even better? In HS I was doing: .26 sec in 50 free .32 sec. 50 back 1:00 in 100 free Currently: 30 in 50 free 35 in 50 back 1:08 in 100 free