It is a milestone in your life which you should be proud to have reached. Some things get more difficult, but other things in life become so much easier. Embrace because before you know it, you shall be 60. :)
I lost my dad and now my brother passed away so I'm just thankful to still be around at this point. I'm 37, but if I were 50 I would ignore my age and still do all the things I enjoy everyday and be thankful for everyday. Just enjoy your life because you never know how long you have.