Absolutely. My wife just bought a bicycle so she can ride alongside our 3 year old daughter. She was embarrassed that she could only ride for a minute or two. I told her thats fine, just try to add 1 minute per week. She is now up to about 12 minutes.

The same is also true about weight training. I would just tell people that its fine if you can only curl 3 lbs now, but in two years if you are STILL curling 3 lbs you aren't getting anywhere.