Here is a good post on the topic. And here is Mike's, at Danger&Play, take.
In short, The Art Of Manliness states that, to get the most out of time and slow down the perceived speed of the years, you should try new things, change your habits, even if it's just small things. TAOM exemplifies:
When reading D&P and TAOM I realized I don't really experience the problems they are addressing.
Sure, I have gotten more patient with age and nowadays I think it's much easier to wait for things to happen (e.g., for the delayed flight to depart or for the night-time subway to arrive). However I don't really feel the years fly by in an unwanted way.
I think I have just happened to practice non-conformity to my own habits without even realizing it. I just like doing new things, learnings new stuff, testing.... and that causes my brain to use about as much memory space every year, thus making my perception of time uniform over time. Once again, I was lucky in the way I lived my life. I have a lot of luck (or, more likely, my brain hormones are naturally slightly out of balance, making me always feel happy and lucky).
Actually, on my Wall of Wisdom (an Excel sheet with notes, tips & tricks etc) I just found this sentence:
"At least once a month, experiment, try something new or something you are afraid of"
Time perception while holding your breath
I left this comment on D&P (it's not really related to the long term perception of the speed of life but still illustrated how fleeting the notion of time can be):
I have some experience of short horizon perception-of-time tricks
When I hold my breath under water (3 min 33 seconds on Ibiza this July), I start by counting pretty slowly, about 100 counts per minute. The tougher it gets the faster I count, and toward the very end, let's say the last 30 seconds or so, I count the fastest I possibly can, approximately 10 counts per second.
This is probably a completely different aspect of time than what mr 70 [years old] was talking about, but I still find it interesting that I want/need to both count slowly and frantically to be able to endure longer without air.
Why is that?
The first few minutes are just about accumulating time at a leisurely pace, so I simply count at my "comfort cadence", but once it gets hard I want to attain partial goals very quickly and immediately set my eyes on the next one, a target I want to be even closer, since I am on the verge of giving up any second. Consequently I count faster and faster to make every count of 10 or 100 closer.
If I instead counted slower and slower, maybe the [thus changed] time perception would make it easier to hold on, [but that's not my experience]. However, target setting and goal-attaining dynamics make me want to count faster and I just can't make counts of 3 or 5 interesting, whereas 100 is always something to aim for, even if it is counted in just 10 seconds. And even if I planned to give up there, I can often make another count of 100 (in less than 10 seconds)