Wicklow Way Mountain Bike

Hi.
Having done a lot of road cycling over the years I have recently started mountain biking. Started with a few short flat trips and graduated to some good mountain trails. My two longest trips to date have been on the Wicklow Way (I know MTBs are not allowed ). One trip was from Marley Park to Knockree then down the road into Enniskerry for the coffee and back by the same rout. My second was from Knockree to Laragh and back also on WW.
On some of the more difficult parts of the trail I ended up walking like around Prince William seat, Djouce and both sides of the footbridge near Powerscourt.
My question to you more experienced mountain bikers is this? Is it possible for a better rider to cycle this entire trail in both directions and is it my lack of descending or climbing technique that has me walking. I would be very impressed to hear that people are capable of cycling on the really steep and rocky parts.
All comments welcome
Blackvalley.