Its not just the age. Unless you have been studying/working with those topics within the last 6 mos or have accumulated a working habit in the area over many ye

Its not just the age. Unless you have been studying/working with those topics within the last 6 mos or have accumulated a working habit in the area over many years, your working knowledge of any one topic is going to be quite superficial. Most need a space to re-introduce themselves to the topic to perform the relevant context switching required. The human mind forgets alot, but fortunately it is easier to re-learn as needed.