Memories are triggered. The reason I don't think we are going to outsource our memories to Google is that there is a big difference between consciously taking the time to look something up, and instant recognition. Three wonderful books which look at how our memory works are 'Tricks of the Mind', 'Fluent Forever' and 'Moonwalking with Einstein'. These books should be standard reading for every teenager. The tricks would both inspire them and save them a lot of study time. Well, it may lead them to study more because the ideas suggested are fun. They all talk about how awesome our minds are at recognising things that matter to us - using links. The more something matters, the more links there are. Knowing this and creating links is fun because you link things to likely triggers. Rude, Sexy, Funny, Colourful images provide the best triggers. Coming up with them requires creativity which becomes a habit.
The mind is ruthlessly efficient at cleaning out stuff that is 'unimportant'. If you have changed jobs a few times, you may berate yourself when you realise you can't remember the name of an ex-colleague you used to spend lots of time with. The reason time is so useful at healing even the most traumatic of situations is that slowly we create other triggers and eventually the trauma disappears from our thoughts. That is good. Less good is when things that do matter get 'spring-cleaned' because you aren't paying attention to them. Despite the belief that we were going to be working 3 hour weeks by now, most of the people I know are incredibly busy. Once work and immediate family responsibilities are addressed, even if there is some time left - there often isn't any energy left, and there aren't any triggers. People can go months and years without seeing or talking to people that really matter to them. It isn't because these people are unimportant - they just aren't in focus. Slowly there are fewer and fewer triggers that bring them to mind. I wrote about the idea of checklists in 'Order vs Spice'. It feels weird though having a checklist of when last you engaged with people that matter, or did things that matter to you. It is a little too structured.
An alternative way may be to take a hint from the memory kings. They suggest learning lists of things to create triggers. For example, you may learn a list of all the albums of a musician you like. You may learn a list of artists. A list of vegetables. Whatever. The point is that if you recognise something, the mind doesn't ignore it. It automatically goes to the connections. Think of when you learn a 'new' word, and then coincidentally starting hearing it really often. Instead of a checklist, you may try to link the important people in your life to situations or things you know you are going to encounter. In fact, by using the memory tricks, many of these mentalists don't bother with checklists anymore because they are so fixed in their heads. They are constantly looking for triggers and so they live life more consciously.
One of the challenges with being busy, particularly if it is routine that is repeated, is once you know what you are doing autopilot can takeover. If there is one thing that makes time fly, it is not being present.