As we get older, the passage of time can seem to be accelerating. Part of the reason for this is our concept of time is relative, 1 year to a 5 year old is what 10 years is to a 50 year old - that is to say it's 20% of the time they have been on this earth. Time also slips away because we lose clear ways to differentiate one day, week, month, or year from another, we live for the future rather than in the present and we lose ourselves (literally) in all sorts of distractions.
When I was a kid I knew exactly what time of year it was, because there were key dates that my world revolved around - start of school, Christmas, end of school, start of summer, swimming pool opening, 4th of July, swimming pool closing and end of summer.
I was interested in the first snow and start of skiing and sledding, football, basketball, track, and baseball seasons, when the rivers dropped and fishing could start, the onset of spring and the chance to get out of winter clothes and outside more - lots of events to distinguish one time of year from another.
I was acutely aware of how old I was, and how old I wished I was - until I hit 21.
Kids know exactly how old they are, sometimes including the number of months, or fraction of a year when they tell you their age. There are important milestones associated with how old they are; starting pre-school, kindergarten, elementary school, middle school, junior high, high school, getting a drivers license, the right to vote, reaching the legal age to - drink, join the military, get a job.
Once you join the world of work the years can start to fly by. For people who work indoors this may be even more of a slippery slope, since there is no clear difference between one season and another - unless they have outside activities that keep them connected. At least a construction worker, a truck driver or a farmer knows what season it is while he or she is at work.
All the wonderful entertainment, and interesting things, available via the internet, radio, TV, DVD's, magazines, books - make it harder for us to keep in touch with the natural world and can also lull us into a state where time can move at a very fast clip.
Regardless of our occupation, we can slow things down if we find ways to re-enter a childlike sense of wonder by learning and doing new things, and by balancing our life with activities that bring us into contact with the natural world (gardening, walking, biking...etc.)
We can literally slow down and enjoy living in the present moment, appreciating what is right in front of us.