There is this old story about junior bankers that they don’t get a mouse with their laptop during their first weeks, forcing them to learn all the Excel keyboard shortcuts. Whether this story is true or not, it might be a pretty good way for you remember all the shortcuts and speed up your Excel skills.
Here is an example of three keyboard shortcuts I often use in Excel. Especially the paste special > values shortcut is a useful one to know.
Head over to macabacus for the full list of useful Excel shortcuts. The website includes a pdf file with a list of the most important Excel shortcuts to have on hand. The website also includes some macros and custom tool bars, but they seem mainly aimed people working in finance making financial models. You are welcome to share macros and other Excel resources in the comments below.