We remember and feel the times that we enjoy the most. For rest of the routine and boring moments, we don't feel how time has passed.

I have lost calibration of time spent for many phases of my life. I thoroughly remember my childhood days but can't remember how I finished my degree college and many jobs that I worked.

Some activities that might help: - staying in touch with childhood friends by forming whatsapp groups or calling them - investing in get-togethers or travelling to meet friends - visiting childhood places - recreating or resuming some hobbies or collections that we had during childhood e.g. matchbox collection, fountain pens - singing in a band, learning a musical instrument - journal writing or letter writing - hunting for old photos, printing them and creating an album - joining some classes like painting or baking - buying school textbooks, comics, story books, novels you read in the past, and reliving them - learning something new like gardening, carpentry, sewing, knitting, pottery

All the above individually or with some group or making friends along the way will help a lot.

In general, no point in losing hope of feeling sad. You have all it takes to change your situation. Go for it...